My husband was out of town on Father's Day, so I spent it at a potluck with a friend and her extended family. One of the desserts served was a spice cake. I commented on how good it was and asked the girl who made it (I don't even know her name) if she made it from scratch and she said "No, it's a box mix with Diet Coke." Diet Coke? What do you mean? She replaced the oil, eggs, and water with Diet Coke and it turned out great!
So here's the deal:
Substitute a can (or cup and a half) of diet soda for the wet ingredients for a cake mix (I'm not sure it works too well with butter recipes) and it turns out just as good as normal, without the added fat and cholesterol of oil and eggs. Use darker sodas (Coke, Dr. Pepper, etc.) for darker cakes like chocolate and lighter sodas (Sprite, Fresca, etc.) for lighter cakes like yellow.