01 - Cream butter and brown sugar together in a large bowl until light and fluffy. Mix in molasses and eggs until smooth. In a separate bowl, whisk flour, baking soda, ginger, cinnamon, cloves, nutmeg, allspice, and salt. Combine dry ingredients with wet, stirring until a stiff dough forms. Divide dough into two, flatten into discs, wrap in plastic, and chill for at least 1 hour.
02 - Preheat oven to 350°F (180°C). Roll chilled dough on a floured surface to 1/4-inch thickness. Cut shapes for houses, trees, and figures using templates. Place pieces on parchment-lined baking sheets. Bake for 10 to 12 minutes until edges firm. Cool completely on wire racks.
03 - Beat egg whites in a clean, grease-free bowl until foamy. Gradually add powdered sugar and lemon juice while beating until stiff peaks form. Transfer icing to piping bags for construction and decoration.
04 - Use royal icing to glue house pieces, beginning with walls and attaching roofs after the base is set. Allow at least 30 minutes drying time between steps. Decorate houses and figures with icing, candies, sprinkles, and other ornaments as desired.
05 - Place assembled houses, trees, and figures on a large platter or cake board. Dust with powdered sugar to simulate snow for a festive presentation.