I need to make a cake this weekend for someone that wants a 9x13 white cake and a 9x13 chocolate cake side by side, but iced as one cake.
I need to know how to avoid a seam in the middle. Do I just butt the two cakes up to each other and ice as normal or do I need to make the icing thicker?
Put icing on the side of the cake that gets the other cake snuggled up to it. Then pipe a good glob of icing in the seam on top. Using a spatula, press it down into the seam firmly. Ice as normal.