Sift the flour, cocoa powder, baking soda, salt, and spices. Set aside.
Cream the butter and sugar. Mix in the eggs and vanilla extract.
Add in the sifted dry ingredients and mix until just combined. Knead the dough together on the tabletop to ensure even mixing.
Roll between two pieces of parchment to 0.65cm/0.25in. Chill the dough.
Cut out the pieces for the house: 5cm/2in X 3.8cm/1.5in for the roof, 3.8cm/1.5in X 2.5cm/1in for the sides, 4cm/1.6in X 5cm/2in for the front and back. Cut a 1cm/0.4in X 1.6cm/0.6in slit in the center of the front and back pieces.
Bake at 180°C/350°F for about 10–12 minutes.
Allow the cookies to cool before assembling with the icing.
To make the icing, whisk the egg whites to stiff peaks, and slowly add the confectioners' sugar. Mix until fully combined and stiff. Keep covered.
Once iced, allow the icing to firm up overnight before using.