Layers of rich double chocolate cake filled with a light and fluffy whipped crunchy peanut butter buttercream, all covered in silky chocolate ganache buttercream and peanut butter cup pieces. The ultimate chocolate peanut butter-lover’s indulgence for any special occasion.
Being raised by chocolate cake people, I know of no other treat worthy of major celebrations–and of course all the chocolate holidays (read: all holidays). Recently, this cake premiered as a Father’s Day cake, and it very well may make a reappearance at an upcoming birthday. Don’t be shy to also bring it out on the 4th of July, Labor Day, Halloween, Thanksgiving, Christmas, New Years (just a few of the chocolate holidays).
This cake not only takes on the beloved chocolate peanut butter combo, but it goes above and beyond with rich double chocolatey cake layers, light and fluffy whipped {crunchy} peanut butter buttercream, AND silky smooth chocolate ganache buttercream.
About the Recipe
The cake and frosting recipes for this Chocolate Peanut Butter Cup Layer Cake are adapted from Handle the Heat: Best Chocolate Cake, Best Ever Chocolate Buttercream Frosting, and Peanut Butter Buttercream Frosting. While recipe writing is my favorite thing and nearly all the recipes on MAK and Her Cheese are original, Tessa simply got this right. Like really, really, really RIGHT. In every way. So instead of reinventing excellence, we’re combining and adapting it to make a huge, outrageously scrumptious chocolate peanut butter cup cake masterpiece.
Along those lines, I’m also deviating somewhat from my normal posts in that this cake is not intended as a “healthy” or “light” version, per se. This is an all-out, made-with-love, celebratory indulgence assured to captivate a crowd. An important reminder that the occasional dose of butter and sugar in moderation can absolutely play a role in even the healthiest lifestyle. That said, this cake is also made with pure, top-quality ingredients, none of which I would deem intrinsically “unhealthy.” In fact, pure cocoa is rich in nutrients and offers a number of benefits, and the cake can easily be made whole grain with whole wheat pastry flour. No processed junk food, sketchy preservatives, hydrogenated oils or shortening here. Furthermore, the rich chocolate flavor throughout the cake is incredibly satisfying, so each bite goes a very long way.
Chocolate Ganache Buttercream
Starting from the top, this chocolate ganache buttercream frosting will BLOW. YOUR. MIND. Honestly, the best frosting I have ever made, and the secret is so simple.
Chocolate ganache–one of the great loves of my life, chocolate melted and whisked in hot heavy cream–is showstopping all on its own. Pour it over any cake, cheesecake, pie, cookie, or use it for dipping literally anything. What I recently discovered, what should not have been a big surprise, is that this magical chocolate concoction also belongs within buttercream frosting. That is, if you can manage to pour it in the mixing bowl without eating it all first.
The result is a silky-smooth, ultra-creamy chocolate buttercream with a texture reminiscent of a fudgy French silk pie. The ganache balances out the overwhelming sugar load of typical frostings, so the flavor is perfectly sweet and light next to the dark cake, and much more satisfying in my opinion.
Double Chocolate Cake
For the cake, we’re going all out with both cocoa powder and melted chocolate, lending a cake that’s uniquely rich, moist, deep and dark, with a brownie-like fudginess from the additional cocoa butter in the chocolate.
Other ingredients that make this cake special include
- sour cream – for optimal moisture and for acidity, which aids in baking
- brown sugar – adds rich molasses flavor and helps retain moisture
- espresso powder – complements the cocoa to create a deeper chocolate flavor
- almond oil – a healthier alternative to generic vegetable/soybean oil
- more eggs than you’d think belong in a single cake – fatty yolks for the win
Whipped Peanut Butter Buttercream
Between the rich chocolatey layers lies a golden filling of ultra light and fluffy peanut butter buttercream, which comes together in one bowl with just a few simple ingredients. Use crunchy peanut butter for a little added texture, or take the crunch up a notch with chopped up peanuts. Either way, the peanut butter layer delivers that unrivaled WOW factor to an already outstanding chocolate cake. Top with chopped up peanut butter cups to bring it all home.
Chocolate Peanut Butter Cup Layer Cake
Notes
*If available, use Dutch-process cocoa powder and add 1 Tbsp white vinegar to the liquid mixture.
**The chocolate buttercream makes just enough to spread on the top and sides of the cake. Double the recipe for frosting-lovers or if you want to use it between the cake layers as well.
***The peanut butter buttercream makes just enough for a light layer between the cakes. To use over the entire cake, multiply the recipe by FOUR.
Chocolate cake recipe adapted from Tessa Arias at Handle the Heat. Check out her Best Chocolate Cake recipe for more detailed tips on ingredients and baking. Also reference Best Ever Chocolate Buttercream Frosting (originally from Stella Parks via Serious Eats) and Peanut Butter Buttercream Frosting.
Ingredients
For the cake:
- 8 oz (227g) bittersweet chocolate, finely chopped
- 2/3 cup (57g) cocoa powder, sifted*
- 2 tsp instant espresso powder
- 1 cup water, heated to just under boiling point
- 1-3/4 cups (222g) all-purpose or whole wheat pastry flour
- 1 cup (200g) packed light brown sugar
- 1/2 cup (100g) granulated sugar (or replacement that measures 1:1 with sugar)
- 1 tsp fine sea salt
- 1 tsp baking soda
- 14 Tbsp (227g) full-fat sour cream, at room temperature
- 1/2 cup almond oil (or other neutral oil)
- 4 large eggs plus one egg yolk, at room temperature
- 2 tsp vanilla extract
For the chocolate ganache buttercream:**
- 1/4 cup heavy cream
- 2 oz semisweet chocolate, finely chopped (not chocolate chips)
- 1.5 sticks (12 Tbsp) unsalted butter, softened but still cool
- 1 cup (125g) organic powdered sugar, sifted
- 1/2 cup (~45g) cocoa powder, sifted (high-fat Dutch if available)
- 1 tsp vanilla extract
- 1/8 tsp fine sea salt
For the peanut butter buttercream:***
- 1/2 stick (4 Tbsp) unsalted butter, softened but cool
- 3-4 Tbsp crunchy or creamy peanut butter
- 1/2 tsp vanilla extract
- pinch (1/32 tsp) fine sea salt
- 2/3 cup (~80g) powdered sugar, sifted
Instructions
Make the cake:
- Preheat the oven to 350°F. Butter two 8-inch round cake pans and lightly sprinkle with flour.
- In a large heatproof bowl, add the chopped chocolate, cocoa powder, and espresso powder. Pour hot water over mixture. Cover and let stand 5 minutes, then whisk gently until smooth. Set aside to cool to room temperature.
- In a separate, medium bowl, whisk the flour, sugars, salt, and baking soda.
- When the chocolate mixture has cooled, whisk the sour cream, oil, vanilla, eggs and yolk (one at a time) into the chocolate mixture.*
- Then stir in the flour mixture, just until large lumps have disappeared and batter is smooth. Do not to over-mix.
- Pour the batter into the prepared pans. Bake 32 to 38 minutes, or until a toothpick inserted into the center comes out clean. Cool in the pans for 30 minutes, then carefully turn the cakes out onto a cooling rack to cool completely.
Make the chocolate ganache buttercream:
- Finely chop the chocolate and add to a bowl.
- Heat the heavy cream either in a small saucepan or in a microwave-safe measuring up, just until it begins to bubble. (Watch closely if using the microwave so that it doesn't boil over).
- Pour hot cream evenly over the chocolate. Let stand about 5 minutes, then stir until smooth. Set aside to cool to about room temp, or until thickened but still pourable.
- In a mixing bowl with a handheld mixer (or in the bowl of a stand mixer fitted with the paddle attachment), add the (cool yet soft) butter, powdered sugar, cocoa, vanilla, and salt. Mix on low speed until well blended. Then increase the speed to medium and beat about 3 minutes longer, or until light and voluminous, scraping down the bowl as needed.
- Reduce speed to medium-low, and add the cooled chocolate ganache. Continue beating until the frosting has lightened in color and texture, about 2 minutes more, scraping down the bowl as needed. Scrape out into a separate container while preparing the peanut butter frosting.
Make the peanut butter buttercream:
- In the mixing bowl, beat the butter and peanut butter on medium-high speed until light and fluffy, scraping down the sides and bottom of the bowl as needed. Add the vanilla, salt, and powdered sugar, and continue beating until the frosting is smooth, lightened in color, voluminous and fluffy (about another 3 minutes).
Assemble:
- When the cakes are completely cool, set one cake (bottom layer) onto a work surface or stand. Coat the top of the bottom layer in peanut butter frosting, then place the second cake directly on top. Spread the chocolate ganache buttercream all over the outer surfaces (top of upper layer and sides of both layers).
- Finish with chopped up peanut butter cups, if desired.