As a teacher many parents ask to do something in class for their child. I make it clear what is allowed (healthy snacks) and what is not allowed (cake or frosted cupcakes) and that we only have 30 minutes from 10-10:30.
I teach Kinder and our day is already limited. So if we have a Birthday, that becomes our snack. On many occasions I have had parents send or drop by to leave their BIRTHDAY SNACK, which always ends up being a meal.
So, my point is if you decide to celebrate your child's birthday at school, then you, not the teacher is responsible for passing out the food and cleaning up. Oh, and please always talk to your child's teacher first. Dont just show up unannounced!!
FYI: I celebrate every child's Birthday in class. They get a HB crown, sticker and pencil. Then they pick 5-6 friends to be their candles and the rest of the students hold hands and become the cake. We sing HAPPY BIRTHDAY and at the end the Birthday Child blows out their candles (friends) and they fall to the floor. Sometimes they relite, so the Bday child has to blow harder. sometime I have to through water on the cake!

Lots of FUN!!