You can charge the breakfast to your room account if you are set up for charging privilages.
When you book into the resort you will be asked if you wish to leave a Credit Card on account in order to be allowed charging privilages. If you decline leaving a credit card, you are not allowed to charge breakfast or anything else to your room.
Note that you also may leave a cash amount against your room account and this cash amount will allow you to get charging privilages. Howver, be advised that some of the CM's at the front desk have no idea how to process a cash payment when you arrive; so be prepared for a longer check-in process.