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
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- 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
Ingredients
Cake
- 2 cups (224 g) almond flour
- 3/4 cup (136.5 g) Swerve Sweetener, or other granular sweetener
- 6 tbsp dark cocoa powder, or Dutch process
- 1/3 cup (36 g) unflavoured whey protein powder, or egg white protein powder
- 2 1/2 tsp (2.5 tsp) baking powder
- 1/2 tsp (0.5 tsp) salt
- 1/2 cup (115 g) sour cream, softened
- 3 large eggs
- 1 tsp vanilla extract
- 2 to 4 tbsp (2 tbsp) water
Peanut Butter Frosting
- 3/4 cup (193.5 g) creamy peanut butter
- 4 ounces (113.4 g) cream cheese, softened
- 1/2 cup (113.5 g) butter, softened
- 3/4 cup (136.5 g) Swerve Confectioners, or other powdered sweetener
- 1 tsp vanilla extract
- 3/4 cup (178.5 g) heavy whipping cream
Chocolate Glaze
- 1/4 cup (59.5 g) heavy whipping cream
- 1 oz (28.35 g) unsweetened chocolate, chopped
- 1 tbsp Swerve Confectioners
- 1 tbsp 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.
Notes
Nutrition
Nutritional Disclaimer
Please note that I am not a medical or nutritional professional. I am simply recounting and sharing my own experiences on this blog. Nothing I express here should be taken as medical advice and you should consult with your doctor before starting any diet or exercise program. I provide nutritional information for my recipes simply as a courtesy to my readers. It is calculated using MacGourmet software and I remove erythritol from the final carb count and net carb count, as it does not affect my own blood glucose levels. I do my best to be as accurate as possible but you should independently calculate nutritional information on your own before relying on them. I expressly disclaim any and all liability of any kind with respect to any act or omission wholly or in part in reliance on anything contained in this website.
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This looks amazing Carolyn! I was just wondering does the Swerve powdered sugar mix into the icing well without leaving a grainy feel? I was trying to make some Chocolate Buttercream Frosting with Kerrygold butter and I turned Steviva brand (which is a erythritol and Stevia blend) into powder in my Vitamix, but it was so grainy that it was practically inedible. Any advice? Thanks!
I know people like to try to powder their own sweetener but there’s simply no way to get it as fine as commercial brands can do. If you buy powdered Swerve or even ZSweet, you won’t get any grittiness like that.
ZSweet just comes in one form, right? I was checking out their website and just saw granulated. You think it would dissolve enough in the frosting/ganache to not be gritty?
No, Zsweet has a powdered version. You should get some of that for the frosting and ganache.
That seems to be out of stock everywhere, too! Oh dear. haha
Is there a substitute for the swerve sweetener? Stores in my area do not carry that brand 🙁
Thanks!
What do they carry? If you can’t get powdered erythritol, I am not really sure how you can make the glaze. You might be able to make the frosting with liquid stevia or liquid sucralose.
You can ground your sweetner in a coffee grinder if you have one to make it powered.
My batter is so dry and crumbly. Is this correct?
No, it shouldn’t be dry and crumbly at all. Can you add some more liquid? What brand of coconut flour did you use?
I added an extra cup of almond milk and 1 cup of sour cream. Still it was very dry. I used Bob’s
Red Mill coconut flour.
That’s very strange. It should not have been so dry and this recipe, although I tweaked the baking soda vs. baking powder a bit, is something I’ve used many time. Did it come out of the oven yet? I use Bob’s too.
What kind of almond flour did you use?
Just took them out. They look dry and did not flow into a flat surface on top. Not cool enough to remove from pan yet. Fingers crossed. (not sure of the almond flour brand)
I am sorry about that but I am going to guess that it’s your almond flour and that it is too coarsely ground. It may be more almond meal than almond flour. The other possibility is that you mismeasured something. Low carb, gluten-free cake batter is often thicker than ones made with regular flour but it should be a batter still, not a hard crumbly dough. I know this cake recipe works because I’ve used it numerous times. I can’t pinpoint what’s off in your case because I am not in your kitchen! I hope it worked out alright in the end.
I had the same problem. The batter seemed thick. I split it between three 6″ pans – it looked great but the cake portion was a bit dry – not as moist as I am used to. Will definitely try again, wonder if maybe adding an extra egg or coating with a simple syrup made from the swerve mayoisten it up. Thoughts?
What kind of almond flour are you using? If your batter is thick, you simply need to add a bit more liquid to the batter.
Having some good friends over for a long overdue dinner party soon. Have finally found the perfect dessert! You’re the bomb.com Carolyn! -don’t tell my kids I wrote bomb.com! 😉
This looks great! Why is it that you recommend against natural peanut butter for this?
Thanks!
If you want a truly smooth, creamy frosting, most natural peanut butters aren’t going to work very well.
this cake looks amazing! I’m not at all fond of coconut though – does it add much of a coconut taste? and can you suggest a low carb substitute if there is one?
No, it does not taste like coconut at all.
This looks awesome! Are there substitutes for whey powder? What purpose does the whey powder serve in this? It only needs to be low-carb (we are not dairy free or anything). Thank you for the awesome recipes!
Gluten is a protein that helps baked goods rise and hold their shape. In its absence, added protein like whey or hemp help do the same.
im in love.. my birthday is next month and what are my 2 favorite things .. dark chocolate and peanut butter omg !!!
saved me from going off my diet with this masterpiece!!!
Hi! This looks TOTALLY dee-lish! And I think I can make it dairy free pretty easily. The only thing is – that Swerve sweetener really upsets my tummy. Do you have any other suggestions? Would Stevia work and if so do you know the conversion? Thanks! M.
Swerve measures cup for cup like sugar so add in as much stevia as you would sugar in this recipe. I think your ganache will be pretty bitter, though.
I made this yesterday while I was snowed in. Very tasty!
Great way to spend a snow day!
This may possibly change my life. wow. I am thinking valentine’s day dinner dessert!!
🙂
What a success story you have made this recipe to be! In the past I have made the original recipe from Smitten Kitchen, and it is a fabulous cake. All your effort to adapt that recipe to be HEALTHY as well as delicious and beautiful and tasty is SOOO appreciated. Thank you very much, Carolyn.
To other bakers RE: Coconut flour. All recipes use so little that it is good to always have it on hand. One pound will last a very long time. Nuts.com and Tropical Traditions are good sources.
Thanks, Beverly. And you’re right on coconut flour…it lasts a long time and when used in small quantities like this, you don’t get any flavour from it.
So far, my favorite gluten-free recipes have been a combination of almond & coconut flour; it seems to solve the texture issue. And don’t think you won’t like it if you don’t like coconut; it will not last like coconut at all!
Thanks for this recipe; it looks amazing! Would it be possible to substitute monk fruit sweetner for the Swerve? That’s all I have on hand. I know that I wouldn’t need to use as much, so I didn’t know how it might affect the texture.
You should be able to, but it may affect the frosting a little – you may need to add less liquid. Not sure how the ganache will fare, it may end up a little thinner.
You have truly outdone yourself with this cake Carolyn!! I’m in awe of your wonderfulness!! What a beauty!!
Thanks, Brenda! It has my favourite flavours so it was bound to be good!
I’m giddy over this recipe, Carolyn, and I agree that ganache is our decorating superhero!
Because of my allergies, I can’t use coconut flour, but I’m fine with gluten, so I’ll probably sub cake flour.
Weird question: When you squeeze a hand full of coconut flour in your hands, does it slide through your fingers (like bread flour), or does it pack together like confectioners sugar?
I don’t know, I’ve never squeezed coconut flour! I will try it, but it’s very powdery and has the texture of bread flour…except it soaks up way more liquid. If you sub cake flour, you’ll need a bit more. Try 3/4 cup.
LOL! Squeezing the flour sounded naughty!
Thanks for the quick response 🙂
Holy ganache! This looks great, but it’s WAY too much cake for me. I was thinking of halving the recipe and baking in my mega muffin pans. Besides lining with parchment and adjusting baking time, do you think I’d have to change anything else? Oven temp for instance? Also, I think it’s fantastic that you answer all the questions posted. So many bloggers do not. Thank you.
Oven temp would be the same. I don’t know exactly what the baking time would be so start at 12 minutes and check every few minutes after that.
How can this magic be? So beautiful and all my favorite flavors. I wish you could come make this for my birthday tomorrow!
Happy Birthday tomorrow!