1 c. milk
3 tbsp. flour
1 c. sugar
2 sticks butter
1 tsp. vanilla

Add milk to flour; gradually. Stir into a smooth paste. Cook, stirring constantly 5-7 minutes or until thick. Cool thoroughly. Meanwhile, cream butter and sugar with electric mixer 7 minutes. Add cooled flour - milk paste a little at a time. Beat until fluffy 5 minutes. Stir in vanilla. Spread on cake.