This year we made a Hogwarts-inspired gingerbread castle (inspired by the book, not the movies, since trying to bake as many cylindrical pieces of gingerbread as would be required to copy the movie Hogwarts was intimidating).
The recipe for the gingerbread was a Dorie Greenspan recipe, taken from NPR (here); it made a lot of dough, enough to make the entire castle (minus towers) with a single batch. We used melted sugar instead of royal icing to connect the pieces, however. Those amber spheres on the pointed roof are leftover melted sugar, rolled by hand into a ball. The towers are Rice Krispie treat, painted with chocolate. The stained glass windows (the colours are hard to see in the picture) are melted jolly ranchers. The Christmas lights strung along the towers and the front parapet are leftover jolly ranchers, melted and then rolled into shape. The other windows are Werthers Chewy Caramels, but that wasn't a great idea since they loose their shape after a couple of days. The clock was a cinnamon sugar cookie, covered with fondant and painted with edible paint. Hedwig was also made of fondant, and painted with edible paint.