Ingredients

The following ingredients have 18 Servings
  • 1 box (18.25-ounces chocolate cake mix)
  • 1¼ cups whole milk
  • 5 tablespoons all-purpose flour
  • 1 cup granulated sugar
  • ½ cup salted butter
  • ½ cup vegetable shortening
  • 3 cups powdered sugar
  • ½ cup salted butter (melted and cooled to room temperature)
  • 3 ounces semisweet chocolate (melted and cooled slightly)
  • 2 tablespoons whole milk
  • 2 tablespoons hot water
  • 1 teaspoon vanilla extract

Instruction

  • Make the Cake: Mix together the cake mix as directed on package and bake in a 10x15-inch jelly roll pan, greased and/or floured, as instructed on the box. Cool to room temperature.
  • Make the Filling: Meanwhile, combine the milk and flour in a small saucepan and cook over low heat, whisking constantly, until the mixture thickens to the consistency of pudding, about 5 to 8 minutes. Set aside and cool to room temperature.
  • Cream together the sugar, butter and shortening on medium speed until light and fluffy, about 3 minutes. Add the cooled flour/milk mixture and beat on high for 7 minutes. Spread on the cooled cake and refrigerate until set.
  • Make the Icing: In a large bowl, mix together all of the icing ingredients on medium-high speed until creamy and smooth. Spread over the filling on the cake and serve. Cover leftovers with plastic wrap and refrigerate.