Everyone will go nuts over this homemade chocolate frosting recipe that's studded with salty chopped walnuts. Each batch of chocolate cake icing makes enough to frost a basic 13- x 9-inch sheet cake or two 9-inch rounds.
In a medium saucepan stir together butter or margarine, unsweetened cocoa powder and buttermilk. Cook and stir until boiling; remove from heat. Beat in sifted powdered sugar and vanilla with an electric mixer on low speed until blended. Stir in chopped walnuts. Immediately frost the top of one 13x9-inch cake. Makes 16 servings.