Yikes!!! Do NOT make them at home... It's not just the ingredients that need to be kosher for the food to be kosher... but also the workspace. Knives, boards, bowls, counters, storage... it's a huge undertaking if you don't already have a kosher kitchen.
If it's a Jewish School... have you tried asking the school where a good place is? "The bakery I would usually go to is holding them hostage for a million dollars a donut, any good place you know of for less?"
We've got kosher everything up here... but no Hostesshevitz kind of doughnuts!
Although... some KrispyKreme donuts are kosher! All the ingredients are & the plant in NC... but not all the stores. here's from their site:
ARE KRISPY KREME DOUGHNUTS KOSHER?
All of our doughnuts are ingredient Kosher. Our mix plant in Winston-Salem, NC where the mix is made is certified Kosher. In addition, some of our stores, but not all, have been certified Kosher. To get a complete listing of our stores that have been Kosher certified, please call us at 1-800-4KRISPY.