This super moist dark chocolate peanut butter cake marries the flavors of rich dark chocolate and sweet creamy peanut butter—a match made in heaven if ever there was one. Fill and coat the cake with peanut butter frosting, then cover the whole dessert with semi-sweet chocolate ganache, pipe more peanut butter frosting on top… and get ready to swoon, because this is love at first bite.
Meet our newest most eligible bachelor: the dark chocolate peanut butter cake. This cake is rich. Like, ultra-rich. I think the term “filthy rich” might even apply here.
Here’s Why You’ll Swoon Over This Cake
- Cake crumb is fudge-like and moist, yet a little light and spongey.
- Enjoy extra texture from the chocolate chips. (I insist you don’t leave these out! Taste testers said the chocolate chips are a welcome contrast to the smooth frosting and cake… and I agree.)
- Peanut butter frosting packs BIG flavor.
- It’s sweet, but not overly so; the lightly sweetened peanut butter frosting and dark chocolate ganache is a nice break from cloyingly sweet buttercream.
- Very rich! If you’re going to indulge, put this layer cake on the menu.
3 Parts to Chocolate Peanut Butter Cake
Let’s break down each component of this unapologetically indulgent cake:
- Dark Chocolate Cake: We’re starting with the cake batter from this 5-star dark chocolate mousse cake, a reader favorite. The cake batter is essentially the same as this chocolate cake, but we’re using the sour cream variation because it produces a sturdier cake—certainly beneficial for tall and towering layers.
- Peanut Butter Frosting: Slather on a layer of creamy peanut butter frosting between each cake layer, and use it to apply a crumb coat to the exterior of the cake. It’s a scaled-up version of my original peanut butter frosting recipe.
- Chocolate Ganache: Top the whole cake with 2-ingredient semi-sweet chocolate ganache. I originally frosted this cake with a chocolate buttercream, but all of my taste testers said it was simply too rich and too sweet. “Hard to finish a slice,” most said. With chocolate ganache, one taster distinctly said, “I cannot stop eating this.”
My team and I made at least 6 of these cakes during the testing phase and we had some VERY happy neighbors and friends.
A Cake With Serious Chocolate Flavor
You need a handful of basic baking ingredients for the cake batter. The acidity in both sour cream and buttermilk is a must to provide proper leavening. (If desired, see baking powder vs baking soda for more information.) A touch of espresso powder and hot coffee further enhances the chocolate flavor. The cake will not taste like coffee—rather, the two add depth to the cake’s dark chocolate flavor. Feel free to skip the espresso powder and replace hot coffee with hot water.
- Why hot liquid? The hot liquid encourages the cocoa powder to bloom and dissolve.
Chocolate chips take the chocolate flavor to the next level, and, as I mentioned above, they also supply phenomenal texture. Toss them in a little flour before folding into the batter.
Creamy Peanut Butter Frosting
I played around with the ingredients in my usual creamy peanut butter frosting recipe, and made some adjustments in order to yield just the right amount for this cake. You need 5 ingredients:
- Peanut Butter: Use the conventional kind, like Jif or Skippy, rather than natural.
- Confectioners’ Sugar: I know you’ll appreciate that there’s less than 2 cups of confectioners’ sugar, a far cry from the usual 6 or 7 cups required for buttercream on a tall layer cake.
- Heavy Cream: You also need this for the chocolate ganache.
- Vanilla Extract
You’ll end up with 3.5–4 cups (about 850g), which is enough frosting for filling, crumb-coating, and some basic piping on the exterior. This frosting has incredible peanut butter flavor because it’s packed with nearly 2 cups of it! There’s no other way to make it. 😉
2 Ingredient Chocolate Ganache
I won’t go into a lot of detail about how to make the ganache because I have a complete chocolate ganache tutorial for you. You need just 2 ingredients: chopped semi-sweet baking chocolate (about 56–60% cacao) and warm heavy cream.
#1 Success Tip: Wait 20–30 minutes for the ganache to thicken before pouring or spooning onto the cake, which is convenient because you also have to wait for the crumb-coated cake to chill.
As you can watch in the video tutorial below, a chilled cake helps set or solidify the ganache as you’re applying it, which helps prevent major drips/big messes.
How to Assemble & Decorate This Chocolate Peanut Butter Cake
I’m NOT a professional cake decorator and with all of my layer cakes, I prefer simplicity. Let me share how I stack and decorate this beauty:
Assemble: Place the bottom cooled cake layer on your cake stand or serving plate. Using a large icing spatula or small offset spatula, evenly cover the top with about 1 cup of peanut butter frosting. Top with 2nd cake layer and another 1 cup of frosting. Top with the third cake and then spread a thin layer of the peanut butter frosting on top and around the sides as a crumb coat. Run a bench scraper around the cake to smooth it out. Refrigerate the cake for at least 30 minutes and up to 3 hours to set the crumb coat.
Decorate: Pour slightly cooled chocolate ganache on top, then, once again, run a bench scraper around the sides to smooth it out. Finally, fill a piping bag with the remaining peanut butter frosting and pipe around the edges of the cake. I use Wilton 1M for the piped detail. If desired, you can finish off this chocolate peanut butter bombshell with peanut butter cups.
If you’re just learning how to use piping tips, my piping tips guide is a helpful resource, and don’t miss this complete list of cake baking success tips.
Now it’s your turn! Swoooon.
This super moist chocolate peanut butter cake combines rich chocolate cake with creamy peanut butter frosting and smooth chocolate ganache. Crumb-coated cake and ganache must chill before assembling and decorating the cake. See recipe Notes for further information about some ingredients.
Peanut Butter Frosting
- Preheat oven to 350°F (177°C). Grease three 8-inch or 9-inch cake pans, line with parchment paper rounds, then grease the parchment paper. Parchment paper helps the cakes seamlessly release from the pans. (See #6 on my top Cake Baking Tips.)
- Make the cake: Whisk the flour, cocoa powder, sugar, baking soda, baking powder, salt, and espresso powder (if using) together in a large bowl. Set aside. Using a handheld or stand mixer fitted with a whisk attachment (or you can use a whisk), mix the oil, eggs, and sour cream together on medium-high speed until combined. Add the buttermilk and vanilla and beat until combined. Pour the wet ingredients into the dry ingredients, add the hot water/coffee, and whisk or beat on low speed until the batter is completely combined. Fold in the flour-coated chocolate chips. Batter is thin and you may see some air bubbles on the surface—that’s normal. You should have about 6–6.5 cups of batter.
- Divide batter evenly between 3 pans. Bake for approximately 24–26 minutes. Baking times vary, so keep an eye on yours. The cakes are done when a toothpick inserted in the center comes out clean.
- Remove the cakes from the oven and set on a wire rack. Allow to cool completely in the pan. The cakes may slightly sink in the middle as they cool—that’s expected.
- As the cakes cool, make the peanut butter frosting: With a handheld or stand mixer fitted with a paddle attachment, beat the butter on medium high speed until creamy and smooth, about 2 minutes. With a rubber spatula, scrape down the sides and bottom of the bowl as needed. Add the peanut butter and beat until completely combined, about 1–2 minutes. Scrape down the sides and bottom of the bowl as needed to help combine. Mixture will be thin. Add confectioners’ sugar, vanilla extract, and salt and then pour in the heavy cream with the mixer running on low speed. After all of the cream has been added, turn the mixer up to medium-high speed and beat for 1–2 minutes, or until fully combined and creamy. Add up to 1/4 cup more confectioners’ sugar if frosting seems quite thin. You should end up with about 3.5–4 cups (850g) of peanut butter frosting. This amount makes enough for the filling, crumb coat, and for a little piping on top.
- Assemble cake + apply crumb coat: Place 1 cake layer on your cake stand or serving plate. Using a large icing spatula or small offset spatula, evenly cover the top with about 1 cup peanut butter frosting. Repeat with 2nd and 3rd cake layers, spreading about 1 cup of peanut butter frosting in between each layer. Spread a thin layer of frosting on the top and around the sides as a crumb coat. Run a bench scraper around the cake to smooth out crumb coat. Chill uncovered in the refrigerator for at least 30 minutes and up to 3 hours to set the crumb coat.
- As your crumb coat sets, make the chocolate ganache: Place finely chopped chocolate in a medium heat-proof bowl. Heat the cream in a small saucepan over medium heat until it begins to gently simmer. (Do not let it come to a rapid boil—that’s too hot!) Pour over chocolate, then let it sit for 2–3 minutes to gently soften the chocolate. With a metal spoon or small rubber spatula, very slowly stir until chocolate has melted and mixture is smooth. Ganache is thin. The finer you chopped the chocolate, the quicker it will melt with the cream. If it’s not melting, do not microwave it. If needed, see Troubleshooting Chocolate Ganache. Once ganache mixture is smooth, let it chill for 20-30 minutes in the refrigerator to thicken before spreading on chilled crumb-coated cake.
- Pour/spoon thickened ganache on chilled cake. Smooth the top with an icing spatula and the sides with a bench scraper. If desired, pipe remaining peanut butter frosting around the edge of the cake. I used Wilton 1M piping tip on the pictured cake. Garnish with peanut butter cups, if desired. Serve cake immediately or chill, uncovered, for up to 4–6 hours before serving. Cake can be served at room temperature or chilled.
- Cover leftover cake tightly and store in the refrigerator for 5 days. I like using a cake carrier for storing and transporting.
- Make Ahead & Freezing Instructions: Prepare cake through step 4. Wrap the individual baked and cooled cake layers tightly and refrigerate for up to 2 days or freeze up to 3 months. Bring to room temperature, then continue with step 5. You can prepare the peanut butter frosting in advance. Cover and refrigerate for up to 3 days. Bring to room temperature before using and beat in a little more room-temperature heavy cream to thin out if necessary. You can also prepare the chocolate ganache ahead of time. Refrigerate prepared ganache for up to 3 days. Bring to room temperature before spreading onto cake. Frosted cake freezes well, up to 3 months. Thaw overnight in the refrigerator, then bring to room temperature or serve cold.
- Cocoa Powder: This recipe requires natural cocoa powder for its acidity, so do not use dutch-process.
- Espresso Powder/Coffee: Espresso powder and coffee will not make the cake taste like coffee. Rather, they deepen the chocolate flavor. I highly recommend them both. If coffee isn’t your thing, you can leave out the espresso powder and use extra hot water instead of the hot coffee.
- Sour Cream: Instead of sour cream, you can use plain yogurt. The cake won’t taste as rich, but it’s a fine substitute.
- Buttermilk: Buttermilk is required for this recipe. You can make your own DIY version of buttermilk if needed. Add 1 teaspoon of white vinegar or lemon juice to a liquid measuring cup. Then add enough whole milk to the same measuring cup until it reaches 1/2 cup. (In a pinch, lower-fat or nondairy milks work for this soured milk, but the cake won’t taste as moist or rich.) Stir it around and let sit for 5 minutes. The homemade “buttermilk” will be somewhat curdled and ready to use in the recipe.
- Peanut Butter: To prevent the frosting from separating or coming out too thin or oily, use processed creamy peanut butter such as Jif or Skippy.
- Why Room Temperature? All refrigerated items should be at room temperature so the batter and frosting mix together easily and evenly. Read here for more information.
- Chocolate Ganache: You can use high-quality dark or semi-sweet chocolate chips if needed, but when melting chocolate, I recommend using pure chocolate baking bars (chocolate chips have stabilizers). You can find them right next to the chocolate chips in the baking aisle. I like Bakers or Ghirardelli brands, the ones labeled semi-sweet (56% cacao), which come in 4-ounce (113g) bars.
- Cupcakes: Here’s a very similar recipe for dark chocolate cupcakes with peanut butter frosting. Feel free to fill them with the peanut butter frosting (instead of frosting them with it) and top each with chocolate ganache.
Keywords: dark chocolate peanut butter cake
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