Chocolate & Peanut Butter Mousse Cake

“We are talking serious cake here. The baked cake layer, a combination of devils food and pieces of peanut butter cups, is spooned out out of the center and the cavity is filled with peanut butter mousse and pieces of the scooped-out cake. Ganache and more peanut butter pieces cover the cake. As I told you this is a serious cake.” Elinor Klivans

Chocolate & Peanut Butter Mousse Cake 

Print This Recipe Total time Yield 12Source Elinor KlivansPublished

serves 12


  • 8 ounce peanut butter cups half as wedges half roughly chopped
  • freshly mixed devils food cake batter (enough to halfway fill a 10-inch cake pan
  • 6 ounce cream cheese, at room temperature
  • .75 cup creamy peanut butter, at room temperature
  • .75 cup powdered sugar
  • 1 cup cold heavy cream
  • 1 teaspoon vanilla extract
  • 2 cup chocolate ganache, cooled until thickened but pourable


Preheat the oven to 350 degrees. Butter the bottom and sides of a 10-inch round cake pan. Line the bottom with parchment paper and butter the paper.

Use a rubber spatula to stir the 4 oz. cup of peanut butter pieces into the cake batter. Pour the batter into prepared pan. Bake until the top feels firm when lightly touched and a toothpick inserted in the center comes out clean, about 40 minutes. Cool the cake in the pan on a wire rack for 10 minutes.

Use a small, sharp knife to loosen the cake from the sides of the pan, and invert the cake onto the wire rack. Carefully remove the paper, then loosely place it on the cake. Let the cake cool thoroughly, then discard the paper.

To make the peanut butter mousse, in a large bowl, using an electric mixer on medium speed, beat the cream cheese and peanut butter until smoothly blended. On low speed, mix in the powdered sugar until it is in incorporated. The texture will not look completely smooth. Set aside.

In a clean large bowl, using clean beaters, beat the cream and vanilla on medium-high speed until firm peaks form. Whisk about ⅓ of the whipped cream into the peanut butter mixture. Use a rubber spatula to gently but thoroughly fold in the remaining whipped cream. The mousse will be smooth. Invert the cake onto a serving plate so that it is now top up. Leaving a 1 inch plain edge along the top of the cake, use a small, sharp knife to cut out the center in one piece to create a cavity about 1 inch deep. Break the removed cake into pieces about 1 inch. Use a metal spatula to spread about ⅓ of the mousse in the hollowed out center of the cake. Put the cake pieces over the mousse, mounding them toward the center. Spread the remaining mousse over the cake pieces and cover the cake with it. Refrigerate the cake until the mousse is firm, about 30 minutes.

Use a spatula to spread the ganache over the top and sides of the cake. Scatter the remaining 4 oz. peanut butter cup wedges over the ganache. Use a large, sharp knife to cut the cake, carefully wiping it clean after cutting each slice. Serve cold. 

The cake can be covered and refrigerated for up to 2 days.