1/2 c. milk
3 tbsp. flour
1/2 c. white sugar
1/2 c. butter

Cook the milk and flour until very thick, then cool thoroughly. Add 1/2 cup white sugar to 1/2 cup butter. Beat these two ingredients hard with electric mixer. Add this to the thickened milk and flour and beat well. Add 1 teaspoon vanilla. The longer this is beaten, the better it gets.