In small saucepan over low heat, melt butter. Add cocoa; stir constantly just until mixture begins to boil. Remove from heat; pour into small bowl.
Add powdered sugar alternately with milk, beating to spreading consistency. Blend in vanilla. Spread frosting while warm. About 2-1/4 cups frosting.
PEPPERMINT: Add 1 tablespoon finely crushed peppermint candy to frosting mixture.
Easy Fudge Frosting
1 cup sugar
1/2 stick margarine
1/4 cup Pet milk
6 oz. semi-sweet chocolate chips
1 tsp. vanilla extract
1 cup marshmallow creme
Combine sugar, margarine, and milk in a 1 1/2 qt. dish. Microwave on high 3 to 4( stir after 2 minutes) minutes until bubbly. Stir chocolate chips, marshmallow creme, and vanilla into hot mixture. Mix until well blended.