My mother made the newbie mistake of trying to get something for my sister's birthday while talking to the podium hostess. Had I not been in the bathroom at the time she did that, I would have tried to get her to cease and desist.
They brought out a small white cake that wasn't anything as great as the restaurant's desserts would have been, and they charged around $12-13 for it. I would have said we did not order a cake to avoid this, but I didn't want to upset my mom.