Diet 7UP Lemon Blueberry Cake

Thanks to plainchicken.blogspot.com                                                                                                             

1 box lemon cake mix
2 egg whites
10oz Diet 7UP
1 cup blueberries



Preheat oven to 350 degrees. Whisk together cake mix, egg whites and Diet 7UP. Fold in blueberries. Pour cake into a greased 9x13 pan and bake for 30 minutes. Top with cool-whip.