K.F.
Hi! I don't have a specific recipe, but you could try replacing the oils and most of the sugars w/ applesauce or his favorite jarred baby fruit (or even carrots or sweet potatoes if he can handle that). To prevent him from overindulging, you could prepare his cake in mini-muffin tins, and instead of frosting there are products like no-sugar-added apple/pumpkin butters, too. Try visiting/googling recipe websites for ideas!