A: Can/May I help make Dad's cake this year?
B: Of course, everyone who wants to can help. (a little different from "will get to," but it just sounds better to me...)
That sounds less stiff to me. Though it confuses me a little, because I'd think that the people making the cake are family and not just anyone. If it doesn't matter who the person is, I'd say "anyone" instead of "everyone."