Mix 1 cup milk, 1/2 cup sugar and 1/3 cup flour in saucepan--cook until thickens. Set aside to cool. Beat together 1 cup butter, 3/4 cup powdered sugar and 1 tsp vanilla. Beat quite awhile.
After first mixture is cooled, beat it for about three minutes. Combine both mixtures and beat for 10 minutes.
Servings: