Just found this on Facebook, as a mom of a son with egg and nut allergies cakes are definitely a challenge. I usually use Ener-G Egg Replacer but that doesn't always make the cakes rise like I'd like so we opt for Oreo cookies with frosting.
Diet Pop Cake: 1 box of cake mix of your choice. 1 can of DIET pop of your choice. 1 tub of fat free cool whip. Mix. Bake. Cool. Top with cool whip. Refigerate. ENJOY! The moistest cake you will ever eat!