In a large bowl, stir together the flour, cinnamon, ginger, cloves, salt and nutmeg.
In a small saucepan over medium, combine the molasses, brown sugar, and butter. Stir continuously until the butter is melted and the sugar has dissolved.
Stir the liquid into the flour mixture. Fold all ingredients together with a wooden spoon or silicon spatula. As it starts to come together, use you hands to fold in the last bit of dry ingredients.
Shape the dough into a ball and flatten slightly into a disk. Wrap with plastic wrap and put in the fridge or at least one hour, or over night.
When ready to bake, preheat the oven to 350°F/180°C.
Flour your work surface, then roll out the dough to ⅛-1/4" thickness. Line your baking sheets with parchment.
Use a template or cookie cutter (see info in head note for more) to cut out the house shapes. You will need to use the cutter or template twice to make one house. Scrape up any scraps and re-roll until you've used all the dough. (Or make some houses and some other shapes if you want to use other fun cutters!)
Bake in the oven for 10-12 minutes.
Let the cookies cool completely on a rack before icing.
While cookies are cooling make icing. Sift the icing sugar into a large bowl.
In the bowl of a stand mixer (or using hand mixer), start to beat the egg whites. Then, slowly begin to stir in the sugar and cream of tartar.
When the sugar is incorporated turn your mixer to high and beat until for 5-7 minutes or until the icing is white and thick.
Transfer the icing to a piping bag fitted with a small tipped nozzle.
Ice one side piece cookie to one front piece cookie. Let those pieces harden and connect completely before assembling the rest of the house.
Then, decorate the roofs. Cover the roof pieces completely with icing or using the icing to make decorative patterns. Then liberally sprinkle colorful sugar, sprinkles, or crushed candy over the icing. Let dry completely.
Using the icing as bonding glue, add the other side and back piece to the front and side you already assembled. Then using the icing to add the roof. You can add a line of icing between the two sides of the roof, then add sprinkles if you like.
Let dry.
Serve as they are, or on the lip of a mug full of cocoa or coffee.
Recipe by Cooking is Messy at https://www.cookingismessy.com/2016/12/10/mini-gingerbread-house/