3/4 c. milk
3 tbsp. flour
6 tbsp. butter
6 tbsp. shortening
3/4 c. sugar
1 1/2 tsp. vanilla
1/4 tsp. salt

Cook milk and flour until thick. Cool. Beat butter, shortening, and sugar for 4 minutes in a bowl. Add flour and milk mixture. Beat 4 minutes. Add vanilla and salt.

CHOCOLATE VARIATION: Add 3 tablespoons cocoa.