Devil’s Food Cake with Sinful Chocolate Frosting
If you like a very tall layer cake, double all of the ingredients for four layers instead of two.
Preheat the oven to 325°F. Butter the bottoms and sides of two 9 by 2-inch round cake pans, and line with parchment paper. To make the cake, in the top of a double boiler or in a heatproof bowl over barely simmering water, melt together 4 ounces (1 bar) of the bittersweet chocolate, butter, sugar, and corn syrup, stirring occasionally until smooth. Remove from the heat and set aside. In a medium bowl, sift together the flour, cocoa, and baking soda. Gently mix in the melted chocolate mixture. Add in the eggs, vanilla, and milk and beat with a spoon until well blended. Divide the mixture evenly between the two prepared pans.
Bake for 25 to 29 minutes, until firm to the touch. Remove from the oven and cool on wire racks. When cool, turn out of the pans. While the cake is cooling, make the frosting. In the top of a double boiler, or in a heatproof bowl over barely simmering water, melt the remaining 6 ounces (1 1/2 bar) bittersweet and milk chocolates, stirring occasionally until smooth. Remove from the heat. Beat in the sour cream. Spread one-third of the frosting on top of one cake layer, then set the second layer on top. Use the remaining frosting to spread over the top and sides of the cake. Let sit in a cool spot, but do not chill in the refrigerator. This cake is best if enjoyed within 4 days of baking.