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
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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!
Divine! I’m with you on not being able to decorate cakes & have given up trying. It’s really 20 servings? One rich cake. Your photographs are beautiful & inspiring. Thanks for another incredible recipe.
It’s very rich. We got 20 servings out of it…you could break it into 16 too but your carbs and such would be a bit higher. And you’d be very full afterward!
OMG, here I am, drooling allover my desk at work, reading about your cake! And I’m definitely with you on the chocolate ganache theory, by the way 😉
Test away, and do let me know your conclusions!
Awesome.
Do you have to use the stevia?
No, but if you want it to be sweet enough, I’d add another 1/4 cup Swerve.
That is a gorgeous cake! What is the purpose of the Protein Powder?
Gluten is a protein and helps things rise and hold their shape. I find adding additional protein to my baked goods helps them that way too.
That looks absolutely amazing! I’ve seen seen such a perfect looking gluten-free layer cake.
this looks faaaabulous!! any chance you have a good “yellow cake” recipe around? my hubbs birthday is coming up, and i’d love to surprise him with a yellow cake with peanutbutter frosting, and chocolate ganache 🙂
My Almond Crusted Butter Cake makes a good “yellow” layer cake…switch the almond extract for vanilla and if you want it even more yellow, replace one of the eggs with 3 egg yolks. https://alldayidreamaboutfood.com/2012/01/almond-crusted-butter-cake-low-carb-and-gluten-free.html
Thank you so much for providing a link the the brand and type of Stevia to use in this recipe! 🙂 It’s hard to make different recipes when there are so many kinds and the amounts vary in sweetness on most of them. I can’t wait to bake this for the family! 🙂 Thanks for all the wonderful things that you do for us.
Thanks, Debbie!
Your recipes often call for whey protein – what is your recommended substitute? We are dairy-free and it’s quite hte struggle where baking is concerned.
THat’s easy! Hemp protein and egg white protein powder are perfect substitutes. Hope that helps.
Hi, how much is the substitution for the whey protein over eggwhite protein?
Thanks for replying
They are cup for cup.
Hi Carolyn….this is the holy grail of low carb recipes for me! Everyone I’ve tried is absolutely delicious! I just made your yogurt waffles the other day and OMG, I felt like I was cheating! Thank you so much for taking the time to do this for all of us, your recipes are easy and scrumptious. With this recipe I was wondering if I could use two cake pans instead of three? Also, since I just don’t like coconut flour, could I sub with oat fiber? These are the almond flour recipes that call for just a little coconut flour? Or just use a little more of the almond flour? Thanks so Much~Lisa
Hi Lisa. Thanks so much for your support! Truth be told about this cake, I only had to cake pans. I put 1/3 of the batter into each of the pans, baked them, and then once I flipped them out, I baked the third layer. But you could also bake in 2 cake pans and just do 2 layers. The baking time would be longer, of course.
As for coconut flour…yes, you can sub oat fiber and I’d aim for 1/2 cup. I can’t be sure you will get exactly the same texture. YOu could also do another cup of almond flour, that would be fine but I think the texture won’t be as fine.
That looks spectacular! On the peanut butter, I can’t find any non-natural peanut butter that doesn’t have sugar added. Does your carb count reflect peanut butter with sugar, or without?
Peanut butter with sugar. Skippy Natural, to be exact. I can’t find any truly good creamy PBs that don’t contain sugar either and so when it comes to a truly good frosting, I will use that over the natural versions. I figure it’s a minor “indulgence” when the rest of the cake is entirely sugar free.
Okay, I will look for that. This is on my definitely-make-it list. Your blog is one of my favorites. You always have fantastic looking recipes. Thanks for sharing them!
Adams No-Stir Creamy Peanut Butter. Adams is a natural peanut butter with the oil floating on top, but for this one they added 2% (or less) palm oil so it’s creamy and doesn’t separate. Other than that, just peanuts and salt. 2 tablespoons has 6g carbs, 2g fiber, 1g sugars.
So you saying use Skippy natural pb for this cake I’m on a low carb diet I also only have the whey in a vanilla flavor I also have the Knox which should I use? Is it okay to use Splenda throughout this cake.
I do use Skippy Natural in a cake like this. The vanilla whey should be fine, just don’t add any more vanilla to the batter.
I have a question about swerve. I’ve baked with my own erythritol/stevia blend and baked goods come out great however, it gives unbanked things ( like fudge and icing) a strong cooling effect. Does swerve give this same effect in things that are uncooked?
Most people, including myself, find no cooling effect with Swerve. That’s a large reason I love it so much (and it’s non-GMO). But every palate is different and some people still experience it with Swerve, but only a small portion of people do.
Great thank you, I will get some to try as that was my biggest concern!
I do definitely feel the cooling effect in Swerve in frostings, where it’s mostly the main ingredient, but not in baked goods. It doesn’t bother me anyway.
Good to know! Compared to buttercream frosting, this one is light on the actual sweetener.
I’m the same and my daughter. We made sugar cookie frosting at Christmas with powdered swerve and had to throw it out. We didn’t like that cooling effect, it was weird.
This looks amazing!! Quick question… not being a coffee drinker, these coffee ingredients don’t always come natural… when you state ‘1 tbsp instant coffee,’ does that mean the granules? Or, coffee in its liquid state (already made)?
Thanks!!! Can’t wait to make this cake!!
Yes, granules. I should go back and amend the recipe. It’s actually optional, it just enhances the chocolate flavour. A little trick I picked up from America’s Test Kitchen.
Would you try this recipe for cupcakes? Thank you.
Sure! I think it would make more than 12 cupcakes though. And I’d advise getting the parchment cupcake papers, for easy removal. They work best with low carb recipes.
I made this today using 1/2 the ingredients and made 12 cupcakes. I also skipped the ganache but may make it when I make these again. I find that cupcakes work better for me for portion control because I can’t cut a cake into 20 slices but I can make 20 – 24 cupcakes. They were amazing!
Sounds great to me! 🙂
I have everything but instant coffee. Can I omit it?
Yup, no problem. The coffee is really just something that enhances the chocolate flavour a bit.
I am most definitely making this. It has all the elements of a win.
Thanks, my dear!
Hi! This cake sounds delicious and I will make it this weekend but is there anything I can use instead of the whey protein? any alternative?
The extra protein helps the cake rise and hold its shape. Do you just not like whey or can you not get any? You could use hemp protein or powdered egg whites too. If you can’t get any of that, then try adding some gelatin powder. I am not sure it will work the same way (and you don’t need as much! 1 tbsp of grassfed gelatin or 1 envelope Knox gelatin) but it will help hold the cake together more than if you skip it altogether.
Hi! Thanks for the immediate reply. I have chocolate protein powder at home without added carbs I cant find any flavorless one here in Malta, do you think I can still use the chocolate one? it tastes more like cocoa then anything else…otherwise I will try gelatine powder as you suggested.
Yes, go ahead and use the chocolate one. that should work.