Take the cash
Keep in mind that as long as the money is used for a qualified education expense, it is tax-free. If used for something else, you’ll pay federal and sometimes state income taxes on any gains, as well as a 10% federal tax penalty. States take different approaches to the income tax treatment of withdrawals. For example, withdrawals for K-12 expenses may not be exempt from state tax in certain states. (If that dream scholarship comes through, you are allowed to withdraw the amount of that scholarship with no penalty.)
The amount you originally invested (the principal) will never be taxed, but withdrawing the gains will trigger additional costs. You’ll want to consider your options and carefully craft a strategy that lets you keep as much of your money as possible.