It is carved slightly. This customer did not want to serve very many people. So, I did a 7in dummy on the bottom with two 7in cakes on top. If you use a 6in cardboard in between the two 7in cakes you will have enough support and still have enough room to slightly curve the hat.
The exaggerated top was done by adding a pieces of cupcakes and cake ball crumbs (already mixed with frosting). You just add the extra cake scraps to the top and fill in with the cake ball crumbs. Crumb coat the whole thing and cover with fondant.
The fondant ended up much thinner than I rolled it because gravity was dragging it down a little while I smoothed it. The cake ended up being about 15 inches high. I had a lot of seams to cover up since I was planning on painting the fondant rather than adding strips. To fill the seams I watered down some fondant and made it almost like a spackle. You can fill in seams with wet fingers to get everything smooth. Let it all dry for a couple of hours before painting.
This cake made me so nervous before I began, but ended up going pretty quickly with little issues. I am sure your cake will be wonderful.