Melt margarine in a medium heavy saucepan. Add marshmallows and cook over low heat until melted. Remove from heat, stir in vanilla and Krispies. Moisten spoon with water and press mixture into greased 9" square pan. Let set 30 min, cut in 24 pieces.
Each serving 1 square, 54 calories 1 fruit choice 1/2 fats & oils 9 g carbohydrate, 2 g fat