1. Heat oven to 350°F. Grease and flour two 9-inch round baking pans or one 13x9x2-inch baking pan.
2. Combine butter, sugar, eggs and vanilla in large bowl; beat on high speed of mixer 3 minutes. Stir together flour, cocoa, baking soda, salt and baking powder; add alternately with water to butter mixture, beating until blended. Add candy, if desired. Pour batter into prepared pans.
3. Bake 30 to 35 minutes or until wooden pick inserted in center comes out clean. Cool 10 minutes; remove from pans to wire racks. Cool completely.
4. Frost with ONE-BOWL BUTTERCREAM FROSTING. Just before serving, garnish with peppermint candy, if desired. Makes 12 servings.
ONE-BOWL BUTTERCREAM FROSTING
6 tablespoons butter or margarine, softened
2-2/3 cups powdered sugar
1/2 cup HERSHEY'S Cocoa
1/3 cup milk
1 teaspoon vanilla extract
Beat butter in medium bowl. Add powdered sugar and cocoa alternately with milk, beating to spreading consistency (additional milk may be needed). Stir in vanilla. About 2 cups frosting.
CHOCOLATE CUPCAKES: Fill paper-lined muffin cups (2-1/2 inches in diameter) 2/3 full with batter.
Bake at 350°F for 20 to 25 minutes; cool. Frost. About 2-1/2 dozen cupcakes.