I'm making a smash cake for a party this weekend and the mother just told me she wants an egg free cake due to allergies.  I've been experimenting today and not having much luck.  I'm not sure what I'm doing wrong.  I've tried a recipe which used a mixture of oil, water, and baking powder to replace the egg.  I baked it at the temperature and time in the recipe.  It didn't seem quite done so I ended up baking it until the outside was getting pretty hard and finally the...