the book, Vegan Cupcakes Take Over the World has a Gluten Free cupcake recipe in chocolate and vanilla that does not contain eggs, dairy, tree nuts, peanuts, wheat, barley, or rye. (as long as you make those choices for milk, i.e. sub soy milk for the almond).
The biggest concern I think would be with cross-contamination. You have to have a completely separate 'never-been-used-on-that-allergen- set of tools and pans to make sure you are safe. Depending on the level of severity of the allergies, even using the same mixer will introduce gluten as fine particles of flour can be released from the head (like on a KA).
And I have to say, as a mom of a kid with food allergies, I'm not going to have a hard time trusting that someone else didn't miss something. I'd much prefer that the birthday treat be something like fruit skewers and dip, popcorn balls, or rice krispy treats--or a treat for my son that I provide while the rest of the class has something else. For myself and many of my friends with allergy kids, we'd rather provide for our own and not make a fuss than to try to educate and give recipes and worry about it--and make everyone subject to a bad cupcake because getting an allergy cupcake that passes as a regular one takes a lot of trial and error! I've tasted some nasty attempts at GF and vegan baked goods, and while I appreciate the gesture--I don't see the point in subjecting the whole class to our diet needs. (and that's just THIS mom's perspective