Chocolate Buttermilk Cake with Peanut Butter Filling and Dark Chocolate Buttercream

By Kelli with an I

A dark chocolate cake with a creamy peanut butter filling and coated in the best dark chocolate buttercream.

Ingredients

• Peanut Butter Filling:
• 3 cups all purpose flour
• 2 1/2 cups granulated sugar
• 4 teaspoons baking soda
• 1/2 teaspoon salt
• 1 cup cocoa powder
• 1 1/3 cups vegetable oil
• 1 1/2 cups buttermilk
• 3 large eggs
• 1 teaspoon vanilla extract
• 1 1/2 cups strongly brewed coffee, cooled
• 1 cup peanut butter
• 2 ounces unsalted butter, room temperature
• 4 cups powdered sugar
• 1/2 cup milk
• 1 tsp vanilla extract
• Dark Chocolate Buttercream:
• 6 tablespoons unsalted butter, room temperature
• 2 3/4 cups powdered sugar
• 2/3 cup cocoa powder
• 6 tablespoons whole milk
• 1 teaspoon vanilla extract

Details

Preparation time 30mins
Cooking time 60mins

Preparation

Step 1

1. Preheat oven to 350F. Lightly grease two 9” cake pans. Set aside.
2. In a stand mixer or a large bowl with a hand beater, mix together the flour, sugar, baking soda, salt, and cocoa powder.
3. Add the vegetable oil, buttermilk, eggs, and vanilla. Mix until combined. Slowly pour the cooled coffee down the side of the bowl while mixing constantly.
4. Divide batter into two cake pans and bake 30-35 minutes or until a toothpick inserted in the middle comes out clean. Let cool completely before frosting.
5. To make peanut butter filling: Cream together peanut butter and butter until smooth. Slowly add powdered sugar until mixed in. Add milk and vanilla and mix until fully incorporated. Store the filling at room temperature in an air tight container.
6. To make the dark chocolate buttercream: Cream the butter until smooth. Slowly add powdered sugar until mixed in. Slowly add the cocoa powder until mixed in. Add milk and vanilla until fully incorporated. Store the frosting at room temperature in an air tight container.
6. To frost the cakes: Level the tops of the cakes with a large knife. Spread a thin layer of peanut butter filling on the top of one cake, then stack the second cake on top. Spread another thin layer of peanut butter filling on the topmost cake. Place in the fridge and let chill for 30 minutes. Frost the layered cakes with the dark chocolate buttercream using a flat decorating spatula. Store the frosted cake at room temperature in an air tight container.