L.S.
Check with the teachers, but I would say pick one day. Also, Teachers like easy to serve treats like donut holes, cupcakes and the like. It can get a bit messy having to cut cake for an entire class is what our MDO told us. Also, check to see if any of the other kiddos have food allergies. Fruit cut outs would be very cool imo. I know my son (who's almost 5 btw) would LOVE that. Gift bags are not required. My son's been in Pre-K for 3 yrs now and no one has done this so far. So many of thse toys are chokeable and not good for the 2 yr old crowd in any case.