Beat butter and sugar together in a large bowl until creamy. Stir in molasses and egg yolks.

Combine flour, cloves, ginger, salt, baking powder, baking soda, cinnamon, and nutmeg in a separate bowl. Mix into the butter mixture to form dough.

Wrap dough in plastic and chill it for at least 1 hour.

Prepare templates for walls and roof panels of the house.

Roll out the dough and cut shapes for walls, roof panels, and optional decorations with cookie cutters.

Bake the gingerbread pieces in a preheated oven at 350°F (175°C) for about 10 minutes. Let cool completely and leave to harden overnight.

Prepare icing by whisking 2 egg whites and gradually mixing in 3 ¾ cups confectioners' sugar until peaks form.

Assemble walls of the house using icing as glue. Let the structure stand and set for 2+ hours.

Attach roof panels with icing and set overnight to harden.

Prepare additional icing using the remaining egg whites and confectioners' sugar. Use it to decorate the roof and attach candies.