Gingerbread houses originated in Germany during the 16th century. The elaborate cookie-walled houses, decorated with foil in addition to gold leaf, became associated with Christmas tradition.
Their popularity rose when the Brothers Grimm wrote the story of Hansel and Gretel, in which the main characters stumble upon a house made entirely of treats deep in the forest.
If using a food processor, make 2 batches. First, mix flour, baking powder, sugar, salt and allspice. Mix in butter and add honey, molasse and eggs. Mix until just combined. Wrap up and chill. Divide pastry into 3 pieces. On a floured work surface, roll out each into a 0.12-inch/3 mm thick sheet, no need to prick with a fork – square up – save and chill excess pastry for backup and freeze biscuit sheets.
Prebake frozen biscuit sheet*, one at a time. Grease lightly using cooking spray, top with parchment or silicone mat and baking tray. Prebake at 350ºF (180ºC) oven for 12 min. Carefully, transfer over countertop and cut into desired shapes. Go easy when cutting over a silicone mat. Bake again for 12 to 14 min more; uncovered. Flip each part brown side up (outside of the house). To smooth out biscuit use sand paper. Keep baked crisp ginger biscuit in a low humidity environment.
*Pre-baking biscuit sheet prior cutting out parts provide sharp and clean cuts. Scraps should be saved for snacks.
Beat on high speed egg white, lemon juice and 90% of sugar to stiff peaks (called bird’s beak/bec d’oiseau) – Add more sugar if necessary. To prevent from drying out, keep royal icing covered with a wet towel while in use. Re-whip royal icing if it relaxes too much. Royal icing dries out pretty fast once piped out. Though, it requires a few hours to completely solidify especially thicker decorations. So, wise to wait between steps. Use gelatin sheets to mimic windows and Xmas stencils (pochoir) for detailed work (carefully wipe it off after each use). When assembling towers, roofs and other parts; seal part first with royal icing creating smooth lines and let dry out for 3 hours at room temp or in an hour in a 120ºF/50ºC oven. Then, flip and seal the inside between the joints to strenghten the structure just like using sealant in bathroom. For other fine touch up use small plain and open star pastry tip and a large French pastry tip for xmas tree rosettes. Use silver dragees for ornaments and gold leaf to mimic fire in the oven. Merry Xmas!