6 tbsp. butter
2 c. powdered sugar
1/3 c. cocoa powder
1 c. evaporated milk (not sweetened condensed)

Melt butter in pan. Add all at once remaining ingredients. Bring to boil and stir while boiling 2 to 3 minutes. Sauce will thicken when cooled. If you use a wire whisk it will help make it smooth. Makes about 1 1/2 cups sauce.