Chocolate Angel Icebox Cake
["1 (10-inch) baked angel food cake", "1/2 c. (1 stick) butter or margarine", "2 1/2 c. unsifted powdered sugar", "3 egg yolks", "2 sq. (2 oz.) unsweetened chocolate, melted", "2 tsp. vanilla", "2 Tbsp. milk or 1/2 tsp. rum extract", "2 c. whipping cream", "2 Tbsp. powdered sugar", "cocoa, orange slices or raspberries for garnish"]
["Cut the cake into 3 to 4 equal pieces.", "Cream together the butter and 2 1/2 cups powdered sugar until light.", "Blend in the egg yolks, melted chocolate and milk with the rum and 1 teaspoon vanilla.", "Spread the filling between the layers of the cake.", "Whip cream until stiff.", "Flavor with the 2 tablespoons powdered sugar and the remaining vanilla.", "Frost top and sides of the cake with the whipped cream.", "Chill for 2 to 4 hours.", "Sprinkle with cocoa. Garnish with orange slices or berries if desired."]
["cake", "butter", "powdered sugar", "egg yolks", "chocolate", "vanilla", "milk", "whipping cream", "powdered sugar", "cocoa"]