hm... you might want to call a behaviorist for this! If your dog is snapping at you and guarding her resources from you, there's probably at least a FEW additional problems, like dominance, food aggression, etc. I would NOT grab her muzzle or 'alpha-role' her, because that could leave you with a nice bite and an even more posessive and resentful dog.

Until then, if you have to give her the treats, feed her in her crate so she doesn't bite anyone. Can you rip it into little pieces? If so, hand feed it to her.