Heat oven to 350°F. Grease and flour 13x9-inch pan or spray with nonstick cooking spray. Prepare cake mix as directed on package, using water, oil and egg whites. Spread batter in greased and floured pan. Drop pie filling by heaping teaspoonfuls evenly onto batter.
Bake at 350°F. for 30 to 40 minutes or until edges pull away from pan and top is golden brown. Cool cake in pan for 45 minutes or until completely cooled.
In medium bowl, combine frosting and whipped topping; blend well. Spread over cooled cake.