2/3 c. sugar
1/4 c. flour
1/4 tsp. salt, optional
3/4 c. milk
1 c. cold butter
1 tsp. vanilla

Mix sugar, flour and salt thoroughly. Stir in milk. Cook over medium heat and stir constantly until thick. Remove from heat and pour into mixing bowl. Cool to room temperature or a little cooler. Add 1/2 cup butter a little at a time, cutting into several pieces, and beat at high speed until smooth. Add vanilla and beat well. Chill for a few minutes before decorating. Cake must be refrigerated until serving time. It makes a little more than enough for a 9 x 13 cake.