It could be white chocolate or fondant but I am just guessing. It is a very beautiful cake!!!! The experts here should be able to tell you more than I would because they do this for a living. Hang in there, I am sure someone will answer you soon.
I am thinking its fondant, its a beautiful cake!
It sure is beautiful. How is that not a cake-cutting nightmare? I wouldn't want to cut it !!!
It's like that lovely giant rose cake (which I once attempted as practice but not to serve!!)
I would use fondant with a bit of tylose, but not too much. And to serve, I would bring a box and pull the cake apart, throwing all the flaps into the box with the supports and cardboard and rose petals.