Legal Question in Employment Law in California

You can't do that without legal risks, but why would you want to anyway? Your current employer has to pay you for accrued and unused vacation when you quit anyway. You don't have to pretend to go on vacation to collect it. And you are not legally required to give any particular amount of notice before you quit either, although you have to give 72 hours notice if you want to make your employer legally obligated to have your final paycheck ready on your last day.