I made a cake last weekend using a crusting buttercream recipe from here...but I noticed that as as the cake sat out, the crust layer cracked. Has anyone experienced this? I may have let it crust for too long before going to smooth it out...or maybe I used too much powdered sugar?

Any suggestions would be great!

Most often, it's because the cake isn't on a board that is sturdy enough to support the weight without flexing while moving the cake.

And if you let it crust for too long, then try to smooth it with viva or a roller it can crack instead of just mooshing together. You only need to let it crust just enough so you can touch it without leaving icing on your finger. So it kind of depends on when it cracked....when you were moving it then a board that is a little bendy is a culprit. If it is when you were viva-ing or rolling it might have been sitting too long.

I once had a cake crack when I iced it still frozen. Not sure if that's what caused it to crack but, since I did everything else exactly the same as the previous 250 cakes, I'm guessing the thawing of the cake caused it...