I'm pretty sure they're done with fondant, but they could easily be done with candy clay or even a mix of candy clay and fondant. The "ruffles" are made of individual circles of whatever product using a technique something like this but without frilling the edges or attaching wires, and leaving them more open:
Good luck and HTH.
Well, "I" think they can be done with Candy Clay. But, I like working with Candy Clay more than I do fondant. However, depending on your weather conditions and venue you may want to consider using fondant. In certain conditions the "clay" will soften and your ruffles won't be as "crisp" as they would be with fondant.