Can I freeze sufganiyot if they're not filled?

I'm having a Hanukkah party and I want to make sufganiyot (Israeli donuts).

I've never made them before.

My big question is, can I fry them ahead of time and freeze them, and then fill them the day of the party?

Other questions:

What kind of oil should I use for frying? What, besides strawberry and raspberry jam, are good fillings? Are they okay to eat with just a dusting of powdered sugar and cinnamon, for those who don't like jelly donuts, or do they really need a filling?

Check out the kosher board. Maybe they have some ideas as well.