How to Make Chocolate Icing?

To make chocolate icing beat together 1/3 cup of butter and 1/2 cups unsweetened cocoa powder until fluffy. Then add 2 cups of powdered sugar slowly, and beat until well mixed. Add 1/4 cup of milk and 1 1/2 teaspoons vanilla and continue to beat slowly. Then add another 2 1/2 cups of additional powdered sugar until all lumps are gone and icing is smooth.