There are a few different methods that you can use if you are short on time and need your fondant to dry quickly rather than over a day or two (depending on the thickness.) First, you can mix the fondant with Tylose Powder, a drying agent, before rolling it out or shaping it. You can also dry fondant pieces in the oven. Place the fondant pieces on a lined cookie sheet, then put the cookie sheet in the oven, and turn the oven light on. Pieces should dry within a few hours depending on their size.