6 tbsp. butter, softened
Cocoa (1/3 c. light flavor, 1/2 c. med. flavor, 3/4 c. dark flavor)
2 2/3 c. unsifted powdered sugar
1/3 c. milk
1 tsp. vanilla

Cream butter in small mixer bowl. Add cocoa and powdered sugar alternately with milk. Beat to spreading consistency (additional tablespoon milk may be needed). Blend in vanilla. About 2 cups frosting.