Preheat oven to 350. Prepare a 9" x 13" pan with cooking spray; set aside. In a mixing bowl, combine cake mix, whipped topping mix, and baking powder. In another mixing bowl, combine water, egg whites, oil, and vanilla extract. Mix dry ingredients with wet ingredients just until moistened. Spread mixture into prepared pan. Bake for 25 minutes or until golden brown. Dissolve gelatin powder in 3/4 cup boiling water. Add half cup cold water; set aside. Poke deep holes about 1" apart in cake while still in pan. Pour gelatin mixture into holes. Refrigerate cake. Prepare remaining whipping topping mix according to package directions. Mix until well blended and fluffy. Fold in orange food coloring to desired shade of orange. Immediately frost cooled cake. Chill until ready to serve.