re: “Cooking class” for young children

That's a wide age range. I agree that having everything ready for assembly would be the way to go. Not as much fun and really making it yourself, though.

Are you going to know how large each child's family is in order to feed the family?

We've done make your own pizza birthday parties, but the kids eat the pizza at the party.

I agree with HoustonChick that lasagna or some other Italian pasta dish is a good idea. Baked chicken spaghetti or a mac and cheese that has a protein in it are a few other suggestions. You'll have to have everything chopped and cooked before hand for assembly.

Are they going to take the dessert home, as well?