Bake cake by directions. Remove from pans. Clean pans. Return cool cake to pans. Prick cake with meat fork 1/2 inch apart. Mix strawberry jello and 1 cup boiling water, pour over layer. Repeat with blue-berry jello for 2nd layer. Refrigerate 3-4 hours. Dip pans in hot water to loosen cake. Frost with cool whip.