Irresistibly moist layers of delicious dark chocolate cake frosted with creamy peanut butter frosting and enrobed in rich chocolate ganache!
Chocolate and peanut butter…a flavor duo that’s IMPOSSIBLE for me to resist. Whether it’s a classic Reese’s Peanut Butter Cup or a crispy Nutty Buddy Bar, I could never say no to this incredibly addictive combo.
From Peanut Butter Cups and Peanut Butter Granola Bars to Chocolate Peanut Butter Cupcakes and Peanut Butter Brownie Cookie Sandwiches, I’ve definitely built up a tasty base of chocolate peanut butter recipes over the years. HOWEVER, I still had yet to dedicate a cake to this glorious combo.
That is, until now…
Can you say drop dead gorgeous?
Believe it or not, this cake tastes just as heavenly as it looks…if not more so. With supremely moist layers of chocolate cake, silky smooth peanut butter frosting, chopped peanut butter cups, and a sophisticated “cloak” of rich chocolate ganache, this cake definitely ain’t your typical chocolate peanut butter cake.
It’s also adorned with a myriad of chocolate peanut butter treats, like Reese’s Pieces, peanut butter cups, Nutty Buddy Bars, Pocky, and fudge-covered Nutter Butter cookies! It’s truly the ULTIMATE chocolate peanut butter cake, and you’d be crazy NOT to make it.
Although I’m usually Team Frosting when it comes to cakes and cupcakes, when it comes to this scrumptious beauty, I’m Team Cake ALL THE WAY. I’d even eat this cake on it’s own–it’s THAT good!! It’s so moist that it almost melts in your mouth, and it’s not overly sweet. I’ve actually used this cake recipe in my VERY popular Miss Trunchbull’s Chocolate Cake. The cake was just too good that I had to use it in this cake as well!
Because I like my decorated cakes to be on the taller side, I reduced the measurements from the original cake recipe, so that it would make four 6-inch layers instead of three 8-inch layers. As you can see, this is a DARK chocolate cake. That’s because it’s loaded with DOUBLE the chocolate.
First, a mixture of hot water, espresso powder, and chopped semi-sweet chocolate are combined until completely smooth and melted. You’re essentially combining coffee and chocolate, but I prefer to use instant espresso powder since it’s quicker than brewing a cup of coffee. I’m not really a coffee drinker, but instant espresso powder is one of my favorite pantry staples for the sole purpose of enhancing the chocolate flavor in cakes. It works like a charm, and non-coffee drinkers will NEVER know that it’s in the cake.
The second piece of the chocolate puzzle is cocoa powder. Now, you can either use the natural cocoa powder, which is much lighter in color. Or, you can use Dutch-processed cocoa powder for that extra dark (almost black) shade. My favorite brand of cocoa powder is Hershey’s Special Dark. It’s basically Hershey’s version of Dutch-processed cocoa. It’s darker and richer than natural cocoa powder, and it lends a more decadent dark chocolate flavor to baked goods. This cocoa powder is also MUCH cheaper than most Dutch-processed cocoa powders, so it’s a win-win!
While most cake recipes use butter as the fat, this one actually uses oil. Butter is great for flavor, but it tends to make cakes really dense. The oil gives this cake a perfectly moist crumb without weighing it down. Buttermilk is also added to keep this cake incredibly moist. Oh, and for those of you who rarely ever have buttermilk on hand (who does??), no worries! Just pour 1 Tablespoon of lemon juice or vinegar into a glass measuring cup, then add enough milk to equal one cup. Stir it and let it sit for a few minutes–that’s your buttermilk! Once I discovered this life hack, I NEVER bought buttermilk ever again.
The rest of the cake ingredients are pretty standard–flour, baking soda, baking powder, salt, sugar, eggs, and vanilla. Due to the amount of liquid in this cake batter, it might appear to look pretty runny. Don’t worry though, it’ll bake up just fine in the oven!
Like I said, this cake is SUPER moist. (Sorry for saying “moist” so much.) Unlike my other cakes, which usually only require about 10-15 minutes to cool before removing from the pan, this cake requires AT LEAST 30 minutes. In fact, after it’s had about 20 minutes to cool, I’ll stick it in the refrigerator for about 10-20 minutes to allow it to firm up. This makes it much easier to remove without losing any precious crumbs!
Now that I’ve spent an eternity talking about the cake alone, let’s move onto the peanut butter frosting. I guarantee it’s A LOT less complicated than the chocolate cake. All you have to do is beat some butter, peanut butter, powdered sugar, vanilla, and heavy cream together until silky smooth. You can also use milk in place of heavy cream. However, I’ve found that the heavy cream makes the frosting much lighter and fluffier. It also spreads more smoothly on the cake.
Since the peanut butter frosting just simply wasn’t enough peanut buttery goodness for this cake, I also chopped up some peanut butter cups and sprinkled them over each layer of frosting before placing the next cake layer on top.
And because the chocolate cake, peanut butter frosting, and peanut butter cups just weren’t enough (for my standards at least), I decided to generously drizzle this cake with some rich chocolate ganache. It just wouldn’t be complete without it!
Finally, to give this cake that “wow factor”, I topped it with some Reese’s Peanut Butter Cups (both milk and white chocolate), Reese’s Pieces, Nutter Butter Bars, fudge-covered Nutter Butters, Chocolate Pocky, and chopped honey-roasted peanuts. The possibilities are endless though, so go wild and add whatever candies or treats you desire!
Chocolate Peanut Butter Cake
Ingredients
Chocolate Cake:
- 1 cup boiling water
- 1 ½ teaspoon instant espresso powder
- 3 ounces semi-sweet chocolate chopped or chips
- 1 ⅔ cup all-purpose flour
- 1 ¾ cup granulated sugar
- ¾ cup unsweetened cocoa powder
- 1 teaspoon baking soda
- 1 teaspoon baking powder
- 1 teaspoon salt
- 2 large eggs
- 1 cup buttermilk*
- ½ cup vegetable oil
- 1 ½ teaspoon vanilla
Peanut Butter Frosting:
- 12 Tablespoons unsalted butter softened
- 1 ½ cup peanut butter
- ½ teaspoon salt
- 2 teaspoons vanilla
- 3 cups powdered sugar
- ½ cup heavy cream
For Assembly:
- 5 Reese's peanut butter cups, chopped (snack-size)
Ganache:
- 3 ounces semi-sweet chocolate chopped or chips
- ⅓ cup heavy cream
For Decorating:
- Nutter Butter Cookies
- Peanut butter cups
- Reese's Pieces
- Nutty Buddy Bars
- Chopped peanuts
- Pocky
Instructions
Make the Cake:
- Preheat the oven to 350ºF. Line four 6-inch round cake pans with parchment paper and grease with butter or nonstick cooking spray; set aside.
- In a medium bowl, stir the boiling water, espresso powder, and semi-sweet chocolate together until chocolate has dissolved and mixture is smooth. Set aside to cool.
- In a large mixing bowl, whisk the flour, sugar cocoa powder, baking soda, baking powder, and salt together until combined.
- In another bowl, whisk the eggs, buttermilk, vegetable oil, and vanilla together. Pour wet ingredients into the dry ingredients and stir until smooth. Add the cooled espresso-chocolate mixture, stirring until just combined.
- Divide batter evenly among the four pans and bake in the oven for 30-35 minutes, or until a toothpick inserted in the center of the cake comes out clean. Remove from the oven and allow to cool completely.
Make the Frosting:
- In the bowl of a stand mixer fitted with the paddle attachment, beat the butter, peanut butter, salt, and vanilla together on high until creamy, about 2 minutes. Add the powdered sugar, a cup at a time, until fully incorporated. Mix on high for 2 minutes. Add the heavy cream and continue beating until light and fluffy.
To Assemble:
- Place a cake layer on a cake plate or pedestal. Spread a layer of frosting, then sprinkle a third of the chopped peanut butter cups evenly on top. Place another layer of cake on top, followed by another layer of frosting and chopped peanut butter cups. Repeat steps with the other cake layers, frosting, and chopped peanut butter cups. Chill cake in the freezer for 1 hour.
- Once chilled and solid, frost the entire cake with a thin layer of frosting--this will act as the crumb coat. Chill cake in the freezer for another 30 minutes to set the frosting. Remove the cake from the freezer and frost it with a final layer of buttercream. Return the cake to the freezer while you make the ganache.
- Make the ganache by placing the chocolate in a medium bowl. Pour the heavy cream into a glass measuring cup, and heat in the microwave until it starts to boil. Pour hot cream over the chocolate, cover with plastic wrap, and allow it to sit for a few minutes. Remove the plastic wrap and stir until smooth.
- Using a small spoon, carefully ladle the ganache along the edges of the cake, allowing the ganache to drip down the sides.** Once the sides are done, pour a few tablespoons of the ganache into the center of the cake, and use an offset spatula to fill in the top of the cake.
- Decorate the cake with peanut butter candies and goodies. Slice, serve, and enjoy!
- Cake will keep covered in the refrigerator for up to 5 days.