Decorating Icing

1/4 cup butter
Food color as desired
2 egg whites
1/4 tsp. cream of tartar
4 cups sifted powdered sugar
1 tsp. vanilla
1 to 2 tsp. light cream 

Cut butter and sugar until it resembles corn meal. Add unbeaten egg whites, vanilla and cream of tartar. Beat thoroughly. Stir in cream until frosting is a little stiffer than spreading consistency for pastry tube use. For cookies or cakes, make of spreading consistency.