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.
- 1 and 3/4 cups (219g) all-purpose flour (spoon & leveled)
- 3/4 cup (62g) unsweetened natural cocoa powder* (see note)
- 1 and 3/4 cups (350g) granulated sugar
- 2 teaspoons baking soda
- 1 teaspoon baking powder
- 1 teaspoon salt
- 2 teaspoons espresso powder (optional)*
- 1/2 cup (120ml) canola or vegetable oil
- 2 large eggs, at room temperature
- 3/4 cup (180g) full-fat sour cream, at room temperature
- 1/2 cup (120ml) buttermilk, at room temperature*
- 2 teaspoons pure vanilla extract
- 1/2 cup (120ml) hot water or black coffee*
- 1 cup (170g) mini semi-sweet chocolate chips (tossed in 1 Tablespoon flour)
Peanut Butter Frosting
- 3/4 cup (170g, or 1 1/2 sticks) unsalted butter, softened to room temperature
- 1 and 3/4 cup (440g) creamy peanut butter*
- 1 and 3/4 cup (210g) confectioners’ sugar
- 1 teaspoon pure vanilla extract
- pinch of salt
- 3 Tablespoons (45ml) heavy cream or heavy whipping cream, at room temperature
- 8 ounces (226g) quality semi-sweet chocolate, finely chopped*
- 1 cup (240ml) heavy cream or heavy whipping cream
- optional garnish: chopped or mini peanut butter cups
- Preheat oven to 350°F (177°C). Grease three 9-inch cake pans, line with parchment paper rounds, then grease the parchment paper. Parchment paper helps the cakes seamlessly release from the pans. (If it’s helpful, see this parchment paper rounds for cakes video & post.)
- 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, or around 1400g.
- 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 more about why room temperature ingredients are important.
- 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