D.G.
D. - I just did a search for "milk free & egg free recipes". There are several sites and here is a link for a site for a cookbook with recipes.
http://www.dairyfreeeggfreekidpleasingcookbook.com/
I didn't have a chance to look at any of the other sites and see what all recipes are just online. You might try that search or something similar and see if there is anything you can come up with. Also - you might get with the daycare and see if there is anyway they can let you know a couple of days before a kid brings birthday cake/cupcakes so you can bake one for your son so he can share in the party. Maybe he won't feel so left out then. I would think there is a recipe somewhere for cake & icing that is dairy free and egg free. I will try to keep my eyes & ears open for you on this. HTH....