Good question! You know, many of us that came from baking with eggs have never really stopped to think about WHY we use eggs in the first place! Eggs can be used as a binder and help the baked good rise, as well as provide moisture. This is one of the reasons why it can be so tricky to substitute eggs, because you have to know what the purpose of the egg is in the recipe you're following. Luckily though, there are plenty of easy substitutions that will work just as well (and sometimes better) than eggs.