American Beauty Frosting

American Beauty Frosting 

Double batch quantity in ( )

5 tbsp flour ( 2/3 cup)

1 cup skim milk (2 cups)

1 cup margarine - 2 sticks (2 cups-4 sticks)

1/2 cup shortening (1 cup)

1 cup granulated sugar (2 cups)

2 tsp vanilla ( 4 tsp) 

Whisk flour into milk in a saucepan. Heat until thickened, stirring often to prevent sticking or scorching.  Pour into bowl and cover with plastic wrap. Refrigerate until completely cooled 

Once cool, cream the margarine, shortening and sugar. Add milk mixture and beat ( #8 with the Kitchenaid whisk) for 10 minutes.