In a large bowl, beat together the butter and sugar.
Add the egg and mix; then add the molasses and mix.
Add the flour, baking soda, ginger, and cinnamon, mixing thoroughly.
The dough should be very stiff. Scrape the dough onto a sheet of plastic wrap and pat it flat.
Wrap completely and chill well, at least 2 hours.
Preheat oven to 350°F.
Prepare two parchment-lined cookie sheets – one for the large house pieces and one for the smaller house pieces.
On a floured board, roll out the dough to ¼” thick.
Move the sheet of dough onto a parchment-lined cookie sheet, then cut out the larger house.
Repeat this process for the smaller house pieces.
(Do not cut the pieces before you move the dough because the pieces may warp or stretch when you move them.)
Bake until firm to the touch and lightly golden, about 20 minutes. Baking time will vary by the size of the pieces.
To assemble your house at a later date, lay the pieces flat in an airtight container separated by wax or parchment paper, and store for up to 1 month.
When you are ready to assemble your gingerbread house, you will need to make Royal Icing to use as “glue.”