This Keto Chocolate Peanut Butter Cake is over-the-top delicious. Three layers of tender low carb chocolate cake with sugar-free peanut butter frosting and a rich chocolate glaze. It’s a peanut butter lover’s dream!
Allow me to introduce myself. My name is Carolyn and I have an all-consuming obsession with chocolate and peanut butter. It’s genetic and I’m pretty sure I’ve had this condition since birth.
It’s actually a very common affliction that affects many people worldwide. Chances are good that you have it too! Otherwise you probably wouldn’t even be reading this post.
You know the best cure for this affliction? Cake. A really amazing cake that tastes like eating keto peanut butter cups. Keto Chocolate Peanut Butter Cake is almost always the answer, no matter what the question!
If this flavor combo is your obsession, be sure to check out my Keto Peanut Butter Balls too.
You will love this cake!
I originally dreamed up this beautiful Keto Chocolate Peanut Butter Cake back in 2014. It was delicious back then but my keto baking skills have vastly improved and I decided it needed an update.
I made the cake similarly to my Keto Devil’s Food Cake, as it’s so wonderful and chocolatey. I also re-vamped peanut butter frosting by folding in whipped cream to give it lightness and structure. It was both airy and luscious, and reminiscent to Keto Peanut Butter Mousse.
Finally, I created a chocolate glaze to decorate the cake. It was the perfect consistency to drip down the sides decoratively.
The final cake is just as delicious as the original, but with even fewer carbs! It’s definitely worthy of all your special occasions.
Ingredients you need
This post may contain Amazon or other affiliate links. As an Amazon Associate I earn from qualifying purchases.
- Almond flour: Make sure to use a good finely ground almond flour for the best cake texture. You can also use sunflower seed flour for a nut-free version.
- Sweetener: I used granular Swerve in the cake and powdered Swerve in the frosting and glaze. I also used a little allulose in the glaze to keep it shiny and soft. See the Expert Tips section for other sweetener options.
- Cocoa powder: If you want a dark chocolate cake, use dark cocoa powder.
- Protein powder: Added dry protein like whey protein powder gives keto cakes a lighter texture and more structure. I don’t recommend skipping it, although you can also use egg white or plant-based protein. Do not use collagen as it will make the cakes gummy and hard to cook through.
- Sour cream: Full fat sour cream adds wonderful tenderness to keto cakes and muffins.
- Peanut butter: Any creamy natural peanut butter should work for the frosting. I really like the Santa Cruz brand.
- Cream cheese: Cream cheese gives the frosting more structure without having to add copious amounts of powdered sweetener.
- Whipping cream: Folding whipped cream into the frosting gives it a luscious mousse-like texture.
- Unsweetened chocolate: The chocolate drip glaze really is the perfect finish to a cake like this. Unsweetened chocolate is not the same thing as sugar-free chocolate like ChocZero or Lily’s. Those have been sweetened already.
- Kitchen staples: Eggs, butter, baking powder, vanilla, salt.
Step by Step Directions
1. Prepare the batter: In a medium bowl, whisk together the almond flour, sweetener, cocoa powder, protein powder, baking powder, and salt. Stir in the sour cream, eggs, and vanilla. Stir in the water one tablespoon at a time until the batter is thick but pourable.
2. Bake the layers: Divide batter evenly among 3 greased 8-inch cake pans and bake at 325ºF for 15 to 20 minutes, or until just firm to the touch. Remove and let cool completely in the pans.
3. Prepare the frosting: In a large bowl, beat the peanut butter, cream cheese, and butter together until very smooth, about 2 minutes. Beat in the sweetener and vanilla extract. In a separate bowl, whip the cream until it holds stiff peaks. Fold into the peanut butter mixture until no streaks remain.
4. Frost the cake: Place one layer of cake on a serving platter and spread with about one quarter of the frosting. Top with another layer of cake and another quarter of the frosting. Add the remaining layer of cake and spread the top and sides with the remaining frosting. Refrigerate for one hour to firm up.
5. Prepare the glaze: In a small saucepan over medium heat, bring the cream to a simmer. Remove from heat and add the chopped chocolate. Let sit a few minutes to melt. Add the sweeteners and whisk to combine. Let cool a few minutes to thicken.
6. Decorate the cake: Drizzle the glaze over the top of the cake along the edges, letting it drip down the sides. Smooth the remaining glaze over the top of the cake. Top with keto peanut butter cups and sprinkles, if desired.
Expert tips
Always make sure to prep your cake pans properly. This includes greasing the pan and lining them with parchment paper circles. And then greasing the parchment as well. This ensures that your cakes flip easily out of the pans.
Don’t overbake those cake layers! It’s easy to do and they will end up dry. I touch the tops of my cakes multiple times during baking. The minute they feel dry on top with a little bounce underneath, I get them out of the oven. Watch my video for the Best Tips on Baking Keto Cakes.
Sweetener Options
You can use almost any granular sweetener in the cake layers, but the baking time may change so keep your eye on them. Additionally, any confectioners-style sweetener should work in the frosting. I do find that allulose can make things a little softer so allow it to firm up properly in the fridge before adding the glaze.
Frequently Asked Questions
Not all peanut butter is created equal. Some of the commercial brands are highly processed and full of sugar and preservatives. But natural peanut butter that has no added sugar has only about 5 to 6 grams of carbs per 2 tablespoon serving. Most people find they can use it sparingly on a keto diet without issue.
Keto friendly cake like this Chocolate Peanut Butter Cake is made with alternative flours and sweeteners. In this case, almond flour forms the base of the cake, along with protein powder and sweetener.
If you want to prepare this keto cake ahead, make the cake up to the point of adding the chocolate glaze. Then wrap carefully and refrigerate for up to 5 days. Add the glaze a few hours before serving.
Keto Chocolate Peanut Butter Cake
Equipment
- 3 8-inch metal baking pans
Ingredients
Cake
- 2 cups almond flour
- ¾ cup Swerve Sweetener or other granular sweetener
- 6 tablespoon dark cocoa powder or Dutch process
- ⅓ cup unflavoured whey protein powder or egg white protein powder
- 2 ½ teaspoon baking powder
- ½ teaspoon salt
- ½ cup sour cream softened
- 3 large eggs
- 1 teaspoon vanilla extract
- 2 to 4 tablespoon water
Peanut Butter Frosting
- ¾ cup creamy peanut butter
- 4 ounces cream cheese softened
- ½ cup butter softened
- ¾ cup Swerve Confectioners or other powdered sweetener
- 1 teaspoon vanilla extract
- ¾ cup heavy whipping cream
Chocolate Glaze
- ¼ cup heavy whipping cream
- 1 oz unsweetened chocolate chopped
- 1 tablespoon Swerve Confectioners
- 1 tablespoon allulose granular
Instructions
Cake
- Preheat oven to 325ºF and grease three 8-inch round cake pans well. Line the bottom of the pans with circles of parchment and grease the parchment.
- In a medium bowl, whisk together the almond flour, sweetener, cocoa powder, protein powder, baking powder, and salt.
- Stir in the sour cream, eggs, and vanilla. Stir in the water one tablespoon at a time until the batter is thick but pourable.
- Divide batter evenly among prepared cake pans and bake 15 to 20 minutes, or until just firm to the touch.
- Remove and let cool completely in the pans.
Peanut Butter Frosting
- In a large bowl, beat the peanut butter, cream cheese, and butter together until very smooth, about 2 minutes. Beat in the sweetener and vanilla extract.
- In a separate bowl, whip the cream until it holds stiff peaks. Fold into the peanut butter mixture until no streaks remain.
To Assemble
- Place one layer of cake on a serving platter and spread with about one quarter of the frosting. Top with another layer of cake and another quarter of the frosting.
- Add the remaining layer of cake and spread the top and sides with the remaining frosting. Refrigerate for one hour to firm up.
Chocolate Glaze
- In a small saucepan over medium heat, bring the cream to a simmer. Remove from heat and add the chopped chocolate. Let sit a few minutes to melt.
- Add the sweeteners and whisk to combine. Let cool a few minutes to thicken, and then slowly drizzle over the top of the cake along the edges, letting it drip down the sides.
- Smooth the remaining glaze over the top of the cake. Top with keto peanut butter cups and sprinkles, if desired.
Jan says
Serves 20… Oh you are a funny girl! Hahahaha! But seriously it looks delicious!!
Cici says
I made this a while ago & it was FANTASTIC! I usually try to follow your instructions to a T as I expect to get the same results as you…however; not having any 8″ cake pans – I baked this recipe in (2) 9″ pans & it came out fine. I wanted to make this recipe again, but I can’t remember if I used baking powder, or the baking soda combo. What is the difference between the two?
Carolyn says
Baking soda is pure sodium bicarbonate and it requires an acid (the vinegar) to get it to react and start creating bubbles to help cakes rise. But it requires you to work quickly and get it in the oven quickly…you don’t want your batter to rise before it’s being baked! Baking powder is baking soda plus some starch (often cornstarch but if you can find Hain’s, it uses arrowroot starch, I think) and some cream of tartar or other weak acid. The weak acid means you don’t need to add anything else and the starch helps delay the process of rising so that it doesn’t happen before you get thing into the oven.
Cici says
Thank you for the chemistry lesson!
Kristine says
I’m in the same boat – not having 8 inch cake pans. How long did you bake the cake in 9 inch pans? And at 325? Or increase oven temp? Thanks in advance ????
Carolyn says
Still bake at 325F but I can’t tell you exactly how long, you will just need to keep an eye on it.
Stacey says
Hi I made this last night with a liquid artificial sweetener and while it rose beautifully and was lovely and moist it came out disgustingly bitter. Im pretty sure this was because it was the wrong type of sweetener and I used too much. I cant find Swerve in Australia but have found Natvia for baking http://natvia.com.au/use-natvia/in-baking/ which seems like it may be a better choice. As it has stevia in it already would I omit the Stevia extract and would the amount be the same? Thanks in advance 🙂
Carolyn says
Yes, I can imagine it could be bad if you used only stevia. I’ve never seen Natvia, but looking at the site, it’s much like other erythritol based sweeteners that are combined with stevia (Truvia, etc). You could simply replace the Swerve and still add stevia, or you could replace the stevia with a little more of the natvia. 1/4 tsp should equal about 1/4 cup.
Ami says
I was just wondering is there anything I can substitute for the cream-cheese in the frosting recipe??
Because I absolutely DETEST cream cheese-based desserts (one of the reasons why I HATE most cheesecakes) and cannot stand the sour aftertaste of cream-cheese in desserts.
So I was wondering if I could substitute mascarpone cheese, or something else??
Carolyn says
You can certainly try mascarpone. I will tell you, it can be a little tricky…it can separate when beaten with other ingredients so make sure it’s room temp and treat it gently!
Megan says
Hi Carolyn,
This looks amazing. I’m just getting into low-carb baking, and I’m wondering about the use of Swerve vs. Splenda. Do the sugar alcohols in Swerve help with baked goods? Is there a difference in baking among the different no-calorie sweeteners? I’ve tried to stay away from sugar alcohols, but I’m not sure it that would affect my baking efforts. Thanks!
Carolyn says
Erythritol is very different than other sugar alcohols, since it causes far less GI discomfort for most people. And because it has a crystalline structure, it definitely helps with texture. That said, you could do Splenda in the cake part here, but you would really need powdered Swerve or another powdered erythritol- based sweetener for the frosting. Personally, I think Splenda is the sweetener to stay clear of, since it’s a man-made chemical, but I realize that is personal preference.
Melissa says
Trader Joe’s natural peanut butter has no sugar and is smoother than “normal” peanut butter.
Ed says
Carolyn,
Thanks so much. My girlfriend found this and made it for me. It is amazing. I am a Type II Diabetic and this cake did not mess with my blood sugars. I felt like I was cheating but no bad effects. I have been on the Ideal Protein diet to control my blood sugars. This cake fits in perfectly.
With Ideal Protein I have been off of my insulin and oral meds since April but I wanted chocolate cake. When I cheated with regular cake I paid for it with high blood sugars. Now I can have chocolate peanut butter cake. (two of my favorite things)
Thanks again.
Carolyn says
I am so VERY glad to hear it, Ed.
Sarah says
Hi Carolyn,
I made this cake when you first posted the recipe (I’m now about to make it a second time) and just remembered that I never commented to tell you how fabulous the recipe was! Definitely one of the best of grain free low carb cakes I have ever made (if not THE best – and I’ve made a lot of them!) I agree it was impossible to tell it was low carb/grain free. I followed your instructions exactly, except that I made it as a double layer cake in 2 x 9 inch pans. Thanks so much for the recipe!
Carolyn says
Thanks so much for your feedback!
Dawn says
I’ve tried this twice today with 2 different brands of almond flour. I even sifted the almond flour the second time around and ground any almonds that wouldn’t go through the sifter. I’m just going to have to switch over to the coconut flour cupcakes and hope for better luck. First time around was Now Foods almond flour and I should have known that wouldn’t work because it was very coarse. Second time around was Bob’s Red Mill. Those are the only 2 almond flours available to me in my area.
Carolyn says
Do you ever order online? That’s how I get Honeyville. Also some people have had good luck with taking Bob’s and grinding it a little further in a coffee grinder or magic bullet.
Dawn says
I do order online, but I’m in a time crunch right now (cake is due tomorrow afternoon). The Bob’s is what I did grind in my coffee grinder. Still didn’t rise. Baking Powder was a freshly opened can, so that wasn’t it either. Had to be the almond flour.
Carolyn says
What a shame, I am so sorry.
Dawn says
The coconut flour cupcake recipe turned out perfectly, so it all has worked out! I love the peanut butter cream cheese frosting. It’s to die for (and I’m not even low carb or gluten free).
Janet says
Bob’s now makes a super fine almond meal….found it at Sam’s club in a 3 lb bag for less than $13! Fabulous find.
Carolyn says
I know. It’s the only one I use now.
Sarah says
Hi Carolyn!
Can I omit the swerve and other kinds of sweeteners and just use an erythriol/stevia mix? Would love to bake it but swerve is not available here (I live in Sweden). Also, do you have any suggestion for alternative fillings? My daughter is allergic to peanuts.
Best regards,
Sarah
Carolyn says
For the cake, you can definitely do an erythritol/stevia mix. For the frosting, you need a powdered sweetener, so can you powder erythtritol in something like a coffee grinder? And any nut butter will work for the frosting, too. Is your daughter allergic to all nuts?
Sarah says
Hi!
Thanks for your reply. Oh, so for the frosting, you mean I must have something like (low carb) icing sugar? Well fortunately that is available in the stores so I won’t have to buy a coffee grinder, hehe.
Well my daughter is just 3 years old and the peanut allergy came as a shock when she was eating satay chicken for the first time, I had no idea she had an allergy before that, since neither me, my husband or her older brother are allergic. Since then I haven’t dared let her try eating any kind of nuts. Do you think I can make like a vanilla cream filling instead?
Carolyn says
Yes, vanilla would be wonderful. I’ve got a few vanilla frosting recipes. Here’s one https://alldayidreamaboutfood.com/2013/11/vanilla-bean-coconut-flour-cupcakes-and-teaching-children-about-kindness.html
Tammy says
Wow! This recipe looks and sound so yummy!!! I have everything needed except unflavored whey. Can vanilla be substituted?
Thanks so much!!
Carolyn says
Sure, that should work.
cds says
I baked this cake and took it to friends house and we loved it! My friend and I are low carbing and totally enjoyed it and so did our spouses who are not low carb. Thanks for all you do to make others life easier!
Lena says
I made the original version of this cake from the Smitten Kitchen website for Christmas two years ago. It is one of my favourite cakes, although I have not made it since. So excited to find the low carb version. Thank you thank you!
Elaina says
Hi, I have been trying to eat healthier for the past month but my birthday is in 10 days and I love chocolate. This recipe looks like it would be a good fix for that, but I have extreme allergies to tree nuts. Almond flour would not work for me and I often have reactions to coconut as well. Do you have any suggestions for me in using this recipe and substituting those ingredients?
Thanks!!
Carolyn says
Can you get a hold of some sunflower seed flour? Or even flax meal might work.
Victoria Heath says
Is this recipe able to halve well? I want to make this for my father in-law this weekend who is diabetic and glucose sensitive as well as living a low carb life style. He rarely gets a dessert or treat so I would like to surprise him, but I want to try it out first. Thanks!
Carolyn says
I don’t know, I didn’t try only making half. I think you will be able to cut all the ingredients in half easily enough but baking the layers will be very different. You can do two layers, but they will still be smaller than the ones I made and you will need to watch them carefully. The baking time would obviously be much less. Or you could bake it into a single layer, maybe in a square pan.
Stacie Martin says
Do you know what the conversion would be with Truvia instead of Swerve? That’s all I have.
Stacie Martin says
I do have the liquid Stevia, though
Carolyn says
They both are supposed to measure cup for cup for sugar, so I suppose they would be the same. I can’t say for sure, I don’t use Truvia.
Janet says
Could I make this as a bundt cake?
Carolyn says
I suppose so but you would have too much frosting, I think.
Janet says
I was thinking of omitting the frosting (I want to surprise my husband and he’s not the peanut butter fan that I am) and making it as a bundt cake with the ganache poured over it. Would the baking time be the same?
Carolyn says
I don’t know if the bake time would be the same. I suspect it would be longer.
Janet says
I baked it in a bundt pan for 45 minutes and made a glaze with Swerve, cream and almond milk and it came out beautifully! Thanks so much! Also I’m at about 5400 feet, baking at higher altitude can be tricky, this worked perfectly.
Carolyn says
So glad!
Pan says
I’ve had my eye on this for some time, and with my boyfriend’s birthday coming up, I finally have the perfect excuse! He’s more of a milk chocolate peanut butter guy though. Would you say both the ganache and the cake have a dark chocolate taste? Also, I noticed you didn’t use a cream and chocolate ganache. Would doing so work with this cake? I’m thinking I could get more of a milk chocolate taste that way, by using Lily’s chocolate and cream. Last question, what brand of dark cocoa did you use in the cake? Thank you so much!
Carolyn says
Yes, both cake and ganache have dark chocolate flavours. For the cake, you can lighten it a bit by using a different brand of cocoa powder that’s not dark. And maybe reducing the amount of cocoa powder a bit. The reason I don’t do a cream ganache is because unsweetened chocolate is super-finicky and seizes every time I try to add it to hot cream. But you might have more luck with the Lily’s and cream mixture.
Pan says
Thanks for the response. I’m going to try making a milk chocolate ganache using cream and Lily’s milk chocolate. As for the cake, I don’t want to risk it. I’m going to make it exactly the way you did. What brand(s) of dark cocoa powder have you had success with in this recipe? I’m wondering if the commenters who had issues with the cake not rising used a different cocoa powder. Apparently they have different acidity levels which would affect the leavener.
Carolyn says
I suspect the cake not rising actually comes from using the wrong almond flour (using something more coarse, like almond meal). There’s also the possibility that their baking soda (or powder) was not fresh, which can kill a rise. But it could be the cocoa powder – too many variables! So I suggest you use Honeyville almond flour, if you can get it, Bob’s Red Mill coconut flour and Hershey’s Dark Cocoa powder. Those are the ones I use.
TL says
If I only have almond meal, can I pulse it in my blender to make it a finer texture?
Teri says
I made this cake yesterday and was thrilled with the results! By far one of the best low carb cakes ever. Thanks so much for the recipe.
Carolyn says
Thanks for the feedback! So glad you liked it.
Kaye says
Hello! I’m so excited to try out this recipe tomorrow! One question: would it be fine to replace the almond milk with diluted heavy cream? I’m a bit worried about the carb content in the almond milk.
Carolyn says
Unsweetened almond milk has 3 g of carbs per serving. You are using less than a full serving so I don’t see how it could be an issue. However, just use water if you don’t want to use the almond milk.