Mix and cook 4 tablespoons flour and 1 cup milk until thick. Remove from stove and cool.

Cream 1/2 cup butter and 1/2 cup shortening for 4 minutes at high speed.

Gradually add 1 cup sugar and beat 4 minutes more at high speed.

Add cooled flour mixture and 2 teaspoons vanilla. Beat an additional 4 minutes. Holds up very well in hot weather and stores very nicely in refrigerator or freezer.