Another option I've used for curved pieces, especially when they're odd shapes (like my gingerbread teardrop trailer), is to use oven-proof wire mesh with a flexible baking mat on top.
Kelly Gingerbread-House-Heaven.com
Nov 30, 2011
Help idea by: Charles E. Mason II
You could role out the gingerbread into a round shape big enough to fit the shape you wish but not to thick. Put on parchment paper, bake for half the time pull it out place on a dome shape mold( this could be anything around the house) if you can find anything there home depot is my favorite place. Then bake off the remaining time.
