Fat-Free Frosting

My husband, who is diabetic, and I are watching our weight and trying to cut fat in our diet. For a treat, I make low-sugar cupcakes and muffins. Then I top them with fat-free sugar-free frosting. To make the frosting, I combine a package of fat-free cream cheese with a little vanilla, cornstarch and sugar-substitute. This makes enough frosting to top 24 cupcakes or muffins. Diana B., Olympia, Washington