If you search for cupcake/cookie delivery, you will find quite a few choices. One that is particularly close is
Insomnia Cookies. There are quite a few others.
Piece Of Cake is a local company that will deliver whole cakes (though they do not do special decorating).
Also check out
Uber Eats (or other similar business). They deliver from a variety of different restaurants. I'm not sure if you could get a whole cake using them, but you could do a bit of a variety assortment for him from different places. If you go this route I recommend including
Sublime Doughnuts for at least part of it. The best doughnuts your son will ever have.
I hope this helps. And tell him happy birthday for me.
-Greg