Preheat the oven to 350°F.

Add the molasses, sugar, ginger, cinnamon, allspice, cloves and salt to a saucepan. Cook over medium-high heat, stirring occasionally. Bring the mixture to a boil then remove it from the heat.

Add the cold butter and stir until it is completely melted. The cold butter will help cool the mixture down. Let the mixture sit for a few more minutes until it cools down to a temperature that is warm enough to touch.

Stir in the egg until well combined. Stir in the flour. 

Transfer the dough to the counter and knead it for about 1 minute until it is smooth. If it is too sticky and wet, add additional flour. If it is dry and crumbly, knead in 2 to 3 teaspoons of water.

Roll the dough out on a piece of parchment paper that is the same size as your baking sheets (see notes). Roll the dough to less than 1/4 inch thick. Sprinkle the dough with flour to keep the rolling pin from sticking to the dough.

Place the templates on the dough and cut them out with a knife. Remove the excess dough from the cut-outs then slide the parchment onto the baking sheet. The parchment makes it easy to transfer the cutouts without disrupting the shapes. If you don't have parchment paper, use a spatula to transfer the cutouts to the baking sheet. You may need to straighten the sides after transferring them.

Bake for 12 to 16 minutes. Remove the chimney pieces at 10 to 12 minutes and remove the larger pieces at 14 to 16 minutes. 

Let the pieces cool on the baking sheet (they may break while they are still warm so let them cool down first.) The cookie pieces will appear soft when you take them out of the oven but they will get firm when they cool down. If you want extra-crisp gingerbread pieces refer to the notes below. 

Use the scraps of dough to cut out gingerbread people, trees, and fun shapes or just make cookies to eat. 

Find a base to put the gingerbread house on. The house will be 5-1/2 inches wide by 6-1/2 inches long. 

When the pieces are completely cool, use the icing to glue the pieces together. Start by piping a thick layer of icing to the inside edges of the front and back pieces. Press the sides in place to form 4 walls. 

Let the walls dry for 45 minutes to an hour before starting on the roof. If your icing is thick you shouldn’t need to hold the walls while it dries. If the icing is a bit thin you may need to support the walls with glasses or cans until the walls are set. 

After the walls have a chance to set, pipe along the top edges of the house and gently press the roof pieces in place. The roof will hold in place if the icing is thick enough. If you have thinner icing then you will need to hold the roof in place for several minutes until the icing sets. 

Put the chimney pieces together and let them partially set up before adding the chimney to the top of the roof. 

If you see any gaps along the edges of the roof and walls, fill the gaps in with extra icing. 

Let the house sit for 6 to 8 hours until the icing is completely dry before you start decorating the house. 

Use assorted candy, cookies, and sugar sprinkles to decorate the house. You can add a few drops of water to the icing and thin it out if you want to create “icicles”.