1 pkg. Betty Crocker angel food cake mix
3/4 cup evaporated skim milk
1 envelope unflavored gelatin
3 tbsp. water
1/3 cup sugar
2 tsp. grated lemon or lime peel
1/3 cup lemon or lime juice
Few drops yellow or green food color

Bake cake mix as directed on package. Pour milk into refrigerator trays; place in freezer and chill until partially frozen, about 1 hour. Split cake to make 3 layers.

Sprinkle gelatin on water to soften; place over boiling water to dissolve. In chilled bowl, beat milk and sugar with chilled beaters on high speed until fluffy; beat in lemon peel, lemon juice, food color, and dissolved gelatin until very stiff.

Fill cake layers, spreading each with about 1/3 of the filling; frost top with remaining filling. Freeze cake. Remove from freezer 20 minutes before serving. Because of the filling, refrigerate leftover cake.

16 servings (140 calories each)