Kids really like it when parents do this. It lets them feel like a "star" for the moment. I used to go in to my kid's classes in elementary school and make latkes at Chanukah (we were pretty much the only Jews around where we lived at the time) and both of my kids loved the attention. It's not like they didn't get any at home!
I agree, though. He should have a healthy snack every day. My take on this, after just about a year of going to families' homes to counsel is that birthdays and other holidays are really big deals to some who are struggling in other ways. They do stuff and spend money on things for their kids that they shouldn't because it's meeting some other need, when really it's the day to day stuff that should be attended to. I've seen this across cultures and generations. Most of the clients I work with have more toys and stuff than my own kids had.