I made a chocolate truffle cake last night...(basicly one big brownie)...anyway...in the cake decorating book that I was using, it said to cut both cakes horizonally and fill with chocolate buttercream...which I did, but when I went to put the layers back together again, they just completely cracked and fell apart!!! I gave them plenty of time to cool on a rack...so I know that wasn't the problem...anyone have any suggestions? What am I doing wrong? Thanks!!!

Were your cakes quite thin? I find the thinner the layer the more likely they are to break when you try to reassemble it all (which is why I always bake 2 separate cakes and sandwich those together!)

They were two round 9 x 2 inch cakes, maybe I should be using round 9 x 3 inch pans??? Thanks!!!

I wouldn't have bothered spliting them, just sandwich the two whole cakes together, but that's just me

I think you may have baked the cake too long. A brownie cake should be removed from the oven when the toothpick comes out with some sticky residue on it. This will keep the brownie/cake chewy. if left in too long they will be crumbly and very dry. That is what I have found anyway.