Birthday cake

Maybe you can try Agar Agar Jelly Cakes. Inform them about the allergies before placing order.

Try this. They gt different types of cakes to suit individual needs https://delcies.com/

Try agar agar! They have very nice fancy design these days too and it taste yum!

Yes agar agar! Or if not, maybe a nugget "cake" or his fav food haha

Can your son take coconut milk? Maybe can give him agar agar cake?

Try Emicakes. See if they can omit all those ingredients..

You can try eggless cake which some cake shop they have.

Maybe jelly heart cake??