1 pkg. white cake mix
3/4 c. water
1/3 c. vegetable oil
3 egg whites
2 (6 oz.) containers Yoplait Original Strawberry Yogurt
1 (8 oz.) bowl Cool Whip
Red food coloring

Heat oven to 350 degrees. Grease and flour 13"x9"x2" pan. Beat cake mix (dry), water, oil, egg whites and 1 container yogurt in large bowl. Beat on medium speed 2 minutes. Pour into pan. Bake 35 to 40 minutes or until cake springs back when touched lightly in center. Cool completely. Fold 1 container yogurt and 1 to 2 drops red food coloring into Cool Whip. Spread over top of cake. Garnish with strawberries if desired. Refrigerate any remaining cake.