#1 Prepare cake mix according to package directions. Pour into a waxed paper-lined and greased jelly roll or cake pan (about 16" x 12") bake in a preheated 350°F oven for 12 to 15 minutes or until toothpick inserted into center comes out clean. #2 Let cool invert onto large tray peel off paper. #3 Into same pan, spoon ice cream, smoothing and leveling off surface with a spatula to form an even layer. Freeze ice cream layer until firm. #4 Dip pan in warm water for 10 seconds and unmold onto cake layer. #5 To decorate cake, use blueberries for blue field, sliced strawberries for red stripes and pipe whipped cream for stars and to decorate sides of cake. Freeze. #6 Remove from freezer 10 minutes before serving.