I have a wedding coming up this weekend, each tier is half chocolate and half white. My problem is my chocolate cake somtimes falls apart at the edges. I have tried countless recipes and found I like the WBH the best and confetti cake but I';m so afraid this will happen again for the wedding cake,and I can't possibly try another recipe now. I don't have this problem with the white cake and hardly ever with the yellow. How do I keep my chocolate in one piece.

i put pudding in the mix and it made it denser. i had no problems with the corners.

Oh I know to put pudding in a box mix, but never thought to do it to a scatch cake. you don't have to alter any ingredients?

I think you just need to let it bake a few more minutes.

Excess sugar in a cake formula can cause the cake center to sink after cooling, or to fall apart...

Cake troubleshooting chart:

http://tinyurl.com/2p5bdu

HTH

should I let the cake completely cool in the pan?

does it have to cool top side up?

Is it better to use shortening and flour to coat pans or melted butter?

I let cakes cool completely in the pan, unless I need the pan, and then I give them 5 minutes and turn them out and reuse the pan.

Meh, sometimes they cool upside down, sometimes right side up. Can't see where it makes any difference.

I use pan grease to coat the sides of the pan with waxed paper in the bottom.
Pan grease is a mixture of equal parts bread flour, veg shortening and oil, whipped together. You can store it nearly forever at room temp.