1 tbsp. butter 2 tbsp. cocoa 1 tbsp. cornstarch 1 c. skim milk 2 tsp. sugar substitute 1/8 tsp. salt Melt butter. Combine cocoa, cornstarch and salt; blend with melted butter until smooth. Add milk and sugar substitute and cook over moderate heat, stirring constantly until slightly thickened, remove from heat. Stir in vanilla. Set pan in ice water and stir until completely cold. (Sauce thickens as it cools.) One serving -(1 tablespoon) free exchange.
