1/2 c. butter
1 c. brown sugar
1/4 tsp. salt

Cook over low 2 minutes, stirring constantly. Add 1/4 cup milk and continue stirring until mixture comes to a boil. Blend in 2 1/2 cups sifted powdered sugar. Add 1/2 teaspoon vanilla. Covers 9 x 13 inch cake or cookie sheet bars.