Hi all -
I iced my sheet cakes with my buttercream but once it crusts and I move it cracks. Totally uncool. What can I do?

thicker base under cake will help -- cake is flexing due to weight and size and not enough support.

I use 3 sheets for foam core glued together

plywood would also work, again at least 1/2 thick -- this will be much heavier than foam core tho'

Usually that happens if the cake board under the cake isn't strong enough. When the cake board is too thin, it allows the cake to move slightly and that causes the icing to crack. I recently began using 1/2" foam core under my sheet cakes and haven't had any problems since.

According to Marina Sousa, you can add a little vinegar to your buttercream to help prevent cracking. She says you can't taste it but I've never tried it.

Heavier board on the bottom is really the easier answer tho. I use MDF that I cut to size, covered with a food-safe paper or cake foil

p.s. ---

the 3 sheets of foam core the cheapo $1@ ones I get at DollarTree -- then spray adhesive and a big ol' stack of heavy books to hold them them down until the adhesive sets -- about 1/2 hour.

ditto. Cracking is not a bc issue, its a support issue.