Ingredients

  • 3 1/2 cups all-purpose flour
  • 2 cups good cocoa powder
  • 1 tablespoon baking soda
  • 1/2 teaspoon kosher salt
  • 1 1/2 cups (3 sticks) unsalted butter, at room temperature
  • 1 1/3 cups light brown sugar, lightly packed
  • 1 1/3 cups granulated sugar
  • 4 extra-large eggs, at room temperature
  • 4 teaspoons pure vanilla extract
  • 2 cups buttermilk, at room temperature
  • 1 cup sour cream, at room temperature
  • 1/4 cup brewed coffee
  • Candy-coated chocolates, such as M&M's, for decorating
  • 24 ounces semisweet chocolate chips
  • 1 1/2 cups heavy cream
  • 2 tablespoons light corn syrup
  • 1/2 teaspoon pure vanilla extract
  • 4 tablespoons (1/2 stick) unsalted butter, at room temperature

Method

  • Preheat the oven to 350 degrees F.
  • Butter one 4 x 3-inch round cake pan, one 6 x 3-inch round cake pan and one 8 x 3-inch round cake pan.
  • Line the bottoms with parchment paper, and butter and flour the pans.
  • Sift the flour, cocoa, baking soda, and salt together in a medium bowl.
  • In the bowl of an electric mixer fitted with a paddle attachment, cream the butter and sugars on high speed until light, approximately 5 minutes.
  • Add the eggs and vanilla and mix well.
  • Combine the buttermilk, sour cream, and coffee.
  • On low speed, add the flour mixture and the buttermilk mixture alternately in thirds, beginning with the buttermilk mixture and ending with the flour mixture.
  • Mix the batter only until blended.
  • Divide the batter between the three pans and smooth the tops with a spatula.
  • Bake on the middle rack of the oven as follows: for the 4-inch pan 45 to 50 minutes, or until a toothpick comes out clean; for the 6-inch pan 70 to 75 minutes, or until a toothpick comes out clean; and for the 8-inch pan 85 to 90 minutes, or until a toothpick comes out clean.
  • Cool the cakes in the pans for 10 minutes each on a cooling rack, carefully remove from the pans and allow to finish cooling.
  • For the frosting, place the chocolate chips and heavy cream in a bowl set over a pot of simmering water, stirring occasionally, until the chips are completely melted.
  • Off the heat, add the corn syrup and vanilla and allow the chocolate mixture to cool to room temperature.
  • In the bowl of an electric mixer fitted with the whisk attachment, whisk the chocolate mixture and softened butter on medium speed for a few minutes, until it's thickened.
  • Place a dollop of the frosting on a serving plate to hold the bottom cake layer in place.
  • Place the 8-inch cake on the plate, flat side up.
  • Frost the top and sides of that layer.
  • Place the 6-inch cake in the center of the top of the 8-inch cake, flat side up, and frost the top and sides.
  • Place the 4-inch cake in the center of the top of the 6-inch cake, flat side down, and frost the top and sides.
  • Pipe any remaining frosting decoratively around the cake and decorate with the candy-coated chocolates.