Yummy Cake

1 box of cake mix (any flavor you want works, I use white for the one I make)

2 1/2 cups of diet soda (I used 7-up)

3 egg whites

The cake mix seems really runny, but it bakes up really nicely. Bake at 350 for 25-30 minutes or until its done. Don't over cook it. 

Topping:

1 small container of fat free cool whip

1 small box of sugar free pudding mix or sugar free jello (I use pistachio)

1 cup of diet soda (I used 7-up again)

Mix it all together and spread over the cake. I found that if I let the cool whip get to room temp and mix it with the pudding mix,  it dissolves better than if the cool whip is really cold. Then I add the 7-up. And the cake is best if it is left in the fridge for a few hours or even over night.