Heat oven to 350 degrees Fahrenheit. Grease and flour two 9-inch round baking pans or one 13x9x2-inch baking pan. In large mixer bowl, stir together sugar, flour, cocoa, baking powder, baking soda and salt. Add eggs, milk, oil and vanilla; beat on medium speed of electric mixer 2 minutes. Stir in boiling water (batter will be thin). Pour batter into prepared pans. Bake 30 to 35 minutes for round pans, 35 to 40 minutes for rectangular pan or until wooden pick inserted in center comes out clean. Cool 10 minutes; remove from pans to wire racks. Cool completely. (Cake may be left in rectangular pan, if desired.) Frost with ONE-BOWL BUTTERCREAM FROSTING. 8 to 10 servings.
One-Bowl Buttercream Frosting: In small mixer bowl, beat butter. Add powdered sugar and cocoa alternately with milk; beat to spreading consistency (additional milk may be needed). Blend in vanilla. About 2 cups frosting. High Altitude Directions Decrease sugar to 1-3/4 cups Increase flour to 1-3/4 cups plus 2 tablespoons Decrease baking powder to 1-1/4 teaspoons Decrease baking soda to 1-1/4 teaspoons Increase milk to 1 cup plus 2 tablespoons Bake at 375 degrees Fahrenheit, 30 to 35 minutes for both pan sizes Hershey's is a registered trademark of Hershey Foods Corporation. Recipe may be reprinted courtesy of the Hershey Kitchens.