Step 1: In a large bowl, using an electric mixer, cream together the softened unsalted butter and packed dark brown sugar on medium speed until light and fluffy, about 2-3 minutes. This incorporates air for a tender crumb.
Step 2: Beat in the unsulphured dark molasses and the large egg until well combined. Scrape down the sides of the bowl to ensure all ingredients are fully incorporated.
Step 3: In a separate medium bowl, whisk together the all-purpose flour, baking soda, ground ginger, ground cinnamon, ground cloves, ground nutmeg, and salt. This ensures even distribution of spices and leavening.
Step 4: Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined and a cohesive dough forms. Be careful not to overmix, as this can lead to a tough gingerbread.
Step 5: Divide the dough into two equal portions. Shape each portion into a flattened disc, wrap tightly in plastic wrap, and refrigerate for at least 2 hours, or preferably overnight. Chilling is crucial for dough stability.
Step 6: Preheat your oven to 350°F (175°C). Line several large baking sheets with parchment paper. Prepare your gingerbread house templates (you can find many printable templates online or design your own).
Step 7: On a lightly floured surface or between two sheets of parchment paper, roll out one disc of chilled gingerbread dough to an even 1/4-inch thickness. This thickness is essential for strong, sturdy walls.
Step 8: Place your paper templates on the rolled-out dough and carefully cut out the house pieces using a sharp knife or pizza cutter. Gently remove excess dough (which can be re-rolled) and carefully transfer the cut pieces to the prepared baking sheets.
Step 9: Bake the gingerbread pieces for 10-15 minutes, or until the edges are firm and lightly browned. Baking times may vary, so watch closely. For crisp, sturdy pieces, avoid under-baking.
Step 10: Immediately after removing from the oven, if any pieces have spread or warped, use your templates and a sharp knife to re-trim the edges while the gingerbread is still warm. This creates perfectly straight edges for easier assembly. Let the baked gingerbread pieces cool completely on the baking sheets before handling.
Step 11: To make the royal icing, in a large bowl, combine the sifted powdered sugar, meringue powder, and warm water. Beat on low speed until combined, then increase to high speed and beat for 5-7 minutes until stiff, glossy peaks form. The icing should be very thick and hold its shape. Keep the icing covered with a damp cloth when not in use.
Step 12: To assemble the house, pipe a generous line of royal icing along the bottom edge of one side wall and attach it to your sturdy base (e.g., a cardboard cake board). Pipe icing along the adjoining edge of another wall and press them together firmly. Hold in place for 1-2 minutes until the icing sets slightly. Repeat with all four walls, ensuring they are straight and level. Allow the basic wall structure to set for at least 30 minutes to an hour for stability.
Step 13: Once the walls are stable, pipe icing along the top edges of the walls where the roof pieces will sit. Carefully place the roof pieces onto the house, pressing gently. Pipe a line of icing along the peak of the roof for extra reinforcement. You may need to use cans or small jars to prop up the roof pieces while the icing dries.
Step 14: Allow the entire gingerbread house structure to dry completely, ideally for several hours or even overnight, before beginning the main decoration. This ensures maximum stability.
Step 15: Now, the fun part! Use the remaining royal icing to create 'snow,' 'icicles,' and to attach various candies, sprinkles, gumdrops, pretzels, and other edible decorations to your gingerbread house. Let your creativity shine!