Preheat oven to 350 degrees F (175 degrees C). Grease one 9x13 inch baking pan.

Blend together cake mix, egg whites, 2 cups whipped topping and 1 cup of water. Pour 1/2 the batter into the prepared pan. Sprinkle 1 1/2 cups of the dry frosting mix over batter. Spread remaining batter over frosting mix.

Bake at 350 degrees F (175 degrees C) for 35 to 40 minutes or until cake tests done. Let cake cool then frost with Strawberry Frosting.

To Make Frosting: Blend remaining frosting mix with remaining whipped topping and 1 tablespoon water until easy to spread. Frost cooled cake in pan. If desired you can add 1/2 cup strawberry slices, fresh or frozen (drained) to the prepared frosting.