Ingredients
For the chocolate sponge cake:

  • 8 large eggs, separated
  • ⅔ cup granulated sugar
  • 1 Tablespoon + 2 Tablespoons + ¼ cup unsweetened cocoa powder, divided
  • ⅛ tsp salt
  • 2 Tablespoons brewed cold coffee (leftover is fine)
  • 1 teaspoon vanilla extract

For the filling:

  • 2 ounces cream cheese, softened
  • 1/3 cup peanut butter
  • 1 cup powdered sugar
  • 1 teaspoon vanilla extract
  • 2-4 tablespoons heavy cream
  • About 1/2 cup chopped peanut butter cups (about 9-10 miniature peanut butter cups)

For the topping:

  • 1 cup semi-sweet chocolate chips
  • 2/3 cup heavy cream
  • About 1/2 cup chopped peanut butter cups (about 9-10 miniature peanut butter cups)

Instructions
For the chocolate sponge cake:

  1. Preheat oven to 350°F. Coat a rimmed baking sheet (jelly roll pan) with cooking spray and line with parchment paper. Spray the parchment with more cooking spray and dust with 1 Tablespoon cocoa powder.
  2. Using an electric mixer, beat the egg yolks and granulated sugar on high speed until thick and pale yellow. Add 2 Tablespoons cocoa powder, salt, coffee and vanilla, and beat in.
  3. With clean beaters and a large clean bowl beat the egg whites to form stiff peaks.
  4. Gently fold in about a quarter of the egg whites into the egg yolk mixture.
  5. In three additions, fold in the remaining egg whites.
  6. Spread the batter into the prepared pan and bake for 20 minutes. It will slowly spring back when lightly touched.
  7. While the cake is baking, sprinkle ¼ cup cocoa powder over a clean kitchen towel.
  8. After removing the cake from the oven, cool for a few minutes,and run a knife around the edges of the cake. Invert the cake onto the prepared kitchen towel and remove the parchment paper that is now on top of the cake.
  9. Carefully roll the cake in the kitchen towel and allow to cool completely.
  10. While the cake is baking, make the filling and topping.

For the filling:

  1. Beat cream cheese and peanut butter with a hand mixer until smooth, then beat in the powdered sugar.
  2. Add vanilla and 2 Tablespoons heavy cream and beat until smooth, adding up to an additional 2 Tablespoons heavy cream is necessary to achieve desired consistency.
  3. Stir in 1/2 cup chopped peanut butter cups.

For the topping:

  1. Place chocolate chips and 2/3 cup heavy cream in a microwave safe bowl or measuring cup and microwave for 30-60 seconds. Stir until smooth.
  2. Chill in the fridge until thick and spreadable.
  3. May be stored, wrapped in plastic, in the refrigerator for 24 hours before serving.
  4. Assembling the cake:
  5. Carefully unroll the cake in the towel.
  6. Gently spread the peanut butter mousse filling over the top of the cake, spreading to about a half inch from the sides.
  7. Roll up the cake from short end to short end. Place seam side down.
  8. Carefully frost the cake with the ganache and top with the remaining chopped peanut butter cups.
  9. Refrigerate for at least 1-2 hours before slicing. Slice off the unfrosted ends, if desired.

This article and recipe adapted from this site