3 tbsp. cocoa
1 c. sugar
1/3 c. evaporated skim milk or 1/3 c. water plus 2/3 c. powdered skim milk
1/4 c. butter
1 tsp. vanilla extract

Mix all ingredients, except vanilla. Bring to a boil. Boil good for 1 minute. Remove from heat; add vanilla and beat until thick enough to spread. Frosts a 9 x 13 inch cake.