For hundreds of years, people still make a gingerbread house the same way. And we can't convince grandma to move out of that shoe. CAUTION: this has not been tested in Fairyland, don't know if it is up to code for resistance to damage from the big bad wolf. If you do plan to try this, make sure you heavily grease the formwork. The extra sugar/molasses seems to make it stick to non-stick heated surfaces.
I was left with a lot of construction rubble and debris so I will take it as a lesson learned. The icing used was a ziploc bag filled with some 10x confectioners powdered sugar mixed with a few drops of water to suitable consistency. The tip of the bag was cut and contents piped out.