Rich and decadent, this chocolate peanut butter cake is simply dreamy. The chocolate cake layers have an incredibly tender, moist crumb and a deep chocolate flavor that pairs beautifully with the fluffy peanut butter frosting. A gorgeous chocolate ganache drip, piped buttercream swirls, and chopped peanut butter cups complete the look.
This 3-layer cake recipe yields 12 servings, making it one of my favorite cakes to wow guests at a small gathering. But you can also turn it into a sheet cake to treat a larger crowd! It also keeps well in the refrigerator for up to 5 days, so feel free to make it a night ahead and store it, carefully covered, until you need to serve it. For more peanut butter desserts, try my peanut butter cheesecake, peanut butter cake, and peanut butter blossoms.
Ingredients
These are the key ingredients to achieving the best peanut butter chocolate cake! The full ingredients list with measurements is in the recipe card.
Buttermilk — buttermilk adds flavor and moisture. The acidity in buttermilk will also react with the baking soda for even fluffier cake layers. If you don’t have buttermilk, make my easy homemade buttermilk substitute. Buttermilk really does make the best chocolate peanut butter cake!
Eggs — large eggs add structure and help bind the ingredients in the cake batter for tall and fluffy layers.
Oil — vegetable oil is a must for incredibly moist chocolate peanut butter cake. Using a liquid fat keeps the cake tender when stored in the fridge.
Vanilla — use good vanilla extract for the best flavor. Even though the flavor profile of this cake won’t highlight the vanilla, it enhances the flavor of the chocolate, making the cake taste richer.
Cocoa powder — be sure to use unsweetened cocoa powder.
Hot liquid — you can use hot water or hot coffee. The reason to use a hot liquid is to bloom the cocoa powder, producing a deeper flavor.
Peanut butter buttercream — to make the dreamy buttercream, you need unsalted butter, creamy peanut butter, vanilla, salt, powdered sugar, and whole milk.
Ganache — for the decadent chocolate ganache, you’ll need dark chocolate and heavy cream. You can use chopped chocolate bars or chocolate chips.
Chocolate Peanut Butter Cake Recipe
Video
Equipment
- 3 8 inch cake pans
- Parchment paper
- Stand mixer with paddle attachment or handheld mixer
Ingredients
For the Cake:
- 1 cup buttermilk room temperature (240mL)
- 3 large eggs room temperature
- ¾ cup vegetable oil (180mL)
- 1 tablespoon vanilla extract
- 1 cup unsweetened cocoa powder (100g)
- 2¾ cups all-purpose flour (330g)
- 2¾ cups granulated sugar (550g)
- 2 teaspoons baking soda
- 1½ teaspoons baking powder
- ¾ teaspoons salt
- 1 cup hot water or coffee (240mL)
For the Buttercream:
- 1½ cups unsalted butter softened (340g)
- 1¼ cups creamy peanut butter (325g)
- 1 tablespoon vanilla extract
- ¼ teaspoon salt
- 5 cups powdered sugar (600g)
- 4 to 5 tablespoons whole milk
For the Ganache:
- 4 ounces dark chocolate chopped (113g)
- ⅓ cup heavy cream (80mL)
To Assemble:
- 8 miniature peanut butter cups halved
Instructions
For the Cake:
- Position two oven racks towards the center of the oven. Preheat the oven to 350°F. Spray 3, 8-inch round cake pans with nonstick baking spray and line the bottoms with parchment paper rounds.
- In a medium mixing bowl, whisk together the buttermilk, eggs, oil, and vanilla until smooth.
- In a large mixing bowl, sift the cocoa powder. Add the flour, sugar, baking soda, baking powder, and salt and whisk to combine.
- Add the buttermilk mixture to the flour mixture and stir to combine. (The mixture will be thick. It’s ok if it’s not completely smooth at this point.) Add the hot water or coffee and whisk until the mixture is fully combined and smooth. Divide the batter evenly among the three prepared pans.
- Place two cake pans on one rack and one on the other rack and bake for 20 minutes. Swap the pans between racks and continue baking for 10 to 15 minutes or until the cakes begin to pull away from the sides of the pans and the center springs back when gently pressed. Allow the cakes to cool in the pans for 15 minutes, then invert onto wire racks to completely.
For the Buttercream:
- In the bowl of a stand mixer fitter with the paddle attachment (a large bowl using a hand mixer), beat the butter and peanut butter together on medium-high speed for 2 to 3 minutes, until smooth and fluffy. Beat in the vanilla and salt until just combined.
- With the mixer on low speed, gradually add half of the powdered sugar (300g). Scrape down the sides and bottom of the bowl, then add 4 tablespoons of milk.
- Return the mixer to low speed and add the other half of the powdered sugar (300g). Increase the speed to medium and beat for about 2 minutes until fluffy. If the frosting feels too stiff or grainy, beat in the remaining 1 tablespoon of milk until it is smooth and spreadable.
- Transfer 1 cup of frosting to a piping bag fitted with a large, closed, star tip. Set aside.
To Assemble the Cake:
- Place one cooled cake layer on a cake plate or cake stand. Top with ¾ to 1 cup of frosting and spread it into an even layer to the edges of the cake. Repeat with 2 more cake layers and frosting. Spread the top and sides of the cake with the remaining frosting to cover completely. Add any remaining frosting to the piping bag. Refrigerate the cake for 20 minutes so that the frosting firms up.
For the Chocolate Ganache:
- Meanwhile, place the chocolate in a small, heatproof bowl.
- Warm the cream in a small pot over medium-low heat for 2 to 3 minutes, or microwave on high for 30 seconds until very warm and just steaming (do not let it boil).
- Pour the warm cream over the chocolate and let it sit for 5 minutes. Stir until it is smooth and glossy. (If any pieces of chocolate do not melt, microwave at 50% power for 10 seconds, then stir once again. Repeat until all of the chocolate is melted.) Let it cool until just barely warm, about 15 minutes, stirring occasionally.
- Pour the ganache over the top of the cake and spread it to cover the top and drip down the sides in a few places. Set aside to harden. (You can expedite this by putting it in the refrigerator for 10 minutes.)
- Pipe the reserved buttercream around the top edge of the cake. Place 2 peanut butter cup halves between each dollop.
- Refrigerate the cake for 30 minutes before slicing and serving.
Notes
- I prefer to use hot brewed coffee in the cake batter. If you’ve made my chocolate cake and used coffee instead of water, you know that this cake will not taste like coffee. Instead, coffee acts as a flavor enhancer for a richer, more complex chocolate peanut butter cake.
- Use creamy peanut butter. Crunchy peanut butter or natural peanut butter will not work well for this frosting. I prefer Jif or Skippy brand peanut butter.
- Wrap the cake pans with baking strips for flat layers! You can check out my post on how to bake flat cake layers for instructions on using fabric strips or how to make your own.
Nutrition
How To Make Chocolate Peanut Butter Cake
1. Whisk the buttermilk, eggs, oil, and vanilla extract together in a medium bowl until well combined.
2. Sift the cocoa powder in a large bowl. Then whisk in the flour, granulated sugar, baking soda, baking powder, and salt.
3. Add the wet ingredients to the dry ingredients and stir to combine. Then, add the hot water or coffee and whisk until the mixture is fully combined and smooth. Divide the batter evenly among the three greased 8-inch round cake pans with the bottoms lined with parchment paper.
4. Bake at 350°F for 20 minutes, then swap the pans between racks and continue baking until the center springs back when pressed lightly. Allow the cakes to cool in the pans for 15 minutes, then transfer to wire racks to cool completely.
5. Make the peanut butter buttercream in the bowl of a stand mixer fitter with the paddle attachment (or in a large bowl using an electric mixer). Beat the softened butter and peanut butter together on medium-high speed until smooth and fluffy. Add the vanilla and salt and beat until just combined.
6. While mixing on low speed, gradually add half of the powdered sugar, then add 4 tablespoons of whole milk. Follow with the rest of the powdered sugar. Increase the speed to medium and beat until fluffy.
7. Put 1 cup of frosting into a piping bag fitted with a large piping tip. Set aside. Place a cooled cake layer on a cake plate or cake stand. Top with some frosting and spread it into an even layer. Repeat with the other 2 cake layers. Spread the rest of the frosting all over the top and sides of the cake. Chill for 20 minutes.
8. To make the chocolate ganache, place the chopped dark chocolate in a small heatproof bowl. Warm the heavy cream in a small pot over medium-low heat. Pour the warm cream over the chocolate and let it sit for 5 minutes, then stir until smooth and glossy. Let it cool, stirring occasionally.
9. Pour the ganache over the top of the cake, then spread it using an offset spatula to cover the top and drip down the sides in a few places. Let the ganache set before finishing the decorations.
10. Pipe the reserved buttercream around the top edge of the cake and garnish with peanut butter cups. Chill for 30 minutes before slicing.
Tips For The Best Ganache Drip
- Let the ganache cool slightly. A warm ganache is best for dripping, but you don’t want it so warm that it runs right off the cake or melts the buttercream. If it cools down too much, it becomes too thick to drip. It should feel slightly warm to the touch when it’s ready to drip.
- Chill the cake first. The cold surface helps to set the ganache drip faster.
- Test it first. You can pick one side of the cake or test it on a drinking glass before you try it on the cake. Turn a drinking glass upside down. Spoon a small amount of ganache on the bottom of the glass (which will be facing up since the glass is upside down) and push it over the edge. If the ganache drips slowly, it’s just right and ready to use on the cake! If it drips quickly, let the ganache cool a bit longer. If it doesn’t drip it all, gently warm the ganache slightly, and try the test again.
Decorating Ideas
As I did in this recipe, you can add the chocolate ganache drip, pipe peanut butter swirls on top, and add halved peanut butter cups. You could also swap the peanut butter cups for chopped salted peanuts, chocolate chips, or sprinkles. See my post on how to decorate a cake for even more ideas, and how to make a crumb coat for the best frosted cake!
Can I Bake This As A Sheet Cake?
Yes! To make this into a sheet cake, grease a 9×13-inch cake pan. Pour the cake batter into the pan and bake at 350°F for 40 to 45 minutes or until the center springs back when gently pressed and the edges start to pull away from the sides of the pan. Let the cake cool completely in the pan.
Cut the buttercream recipe in half, whip it up, and spread it over the top of the cooled cake. You can drizzle the ganache over the top of each slice (or skip it altogether) and decorate with an additional piping of frosting and chopped peanut butter cups if you like.
Can I Use Cake Flour Instead Of All-Purpose?
The cake layers are quite tender already with all-purpose flour, so there isn’t a need to, but if that’s what you have on hand, you can certainly make the swap. Check out my post on how to substitute cake flour. You’ll need 3 cups or 336 grams of cake flour.
How To Store
Cover any leftover chocolate peanut butter cake and refrigerate it for up to 5 days. You can also freeze it for up to 3 months. Wrap slices well with plastic wrap and aluminum foil and store in a freezer bag or airtight container in the freezer. Thaw slices for a few hours in the refrigerator before enjoying.
Pro Tips For Making This Recipe
- Weigh the flour. Using too much flour is a common error that will cause the chocolate peanut butter cake to turn out dry. For the most accurate measurement, use a kitchen scale. If you don’t have one, fluff the flour in its container, spoon it into your measuring cup, and use a knife to level off the top.
- Use room temperature ingredients. Set the refrigerated ingredients out in advance so they have a chance to warm to room temperature. This makes them easier to incorporate. The butter will take the longest to soften, so if you forget to set it out, see my tips for how to soften butter quickly.
- Let the cake layers cool completely before frosting. Otherwise, the frosting will melt and slide off or cause the layers to be unstable.
Frequently Asked Questions
You can! This chocolate peanut butter cake recipe will make roughly 24 cupcakes. Bake them for about 20 minutes. You can also make my chocolate cupcakes and top them with peanut butter frosting. Add a ganache drip to each cupcake and a peanut butter cup for extra flair!
You can use unsweetened natural cocoa powder or unsweetened Dutch-processed cocoa powder. I use Dutched cocoa powder because I like the richer chocolate flavor. Avoid sweetened cocoa powder, as that will make the cake far too sweet and affect how the cake bakes.
If it is a creamy, no-stir nut butter, it should work fine instead of peanut butter. This frosting doesn’t work well with natural nut butters that separate or crunchy nut butters. Taste the frosting as you add powdered sugar to test for flavor and texture. You may need a bit more or less powdered sugar than the recipe calls for, depending on the type of nut butter you use.
If you’ve tried this chocolate peanut butter cake recipe, then don’t forget to rate it and let me know how you got on in the comments below. I love hearing from you!
