In very large bowl, with wire whisk (or with an electric mixer), beat brown sugar, cream, and molasses until sugar lumps dissolve and mixture is smooth. In medium bowl, combine flour, baking soda, and ginger. With spoon, stir flour mixture into cream mixture in 3 additions until dough is too stiff to stir, then knead with hands until flour is incorporated and dough is smooth.
Divide dough into 4 equal portions; flatten each into a disk to speed chilling. Wrap each disk well with plastic wrap and refrigerate at least 4 hours or overnight, until dough is firm enough to roll.
Grease and flour large cookie sheets (17-inch by 14-inch/43x36cm)
Roll out dough, 1 disk at a time on each cookie sheet to about 3/16-inch thickness. (Placing 3/16-inch dowels or rulers on either side of dough to use as a guide will help roll dough to uniform thickness.)
Trim excess dough from cookie sheet; wrap and reserve in refrigerator. Chill rolled dough on cookie sheet in refrigerator or freezer at least 10 minutes or until firm enough to cut easily.
Preheat oven to 300 degrees F (149C)
Use chilled rolled dough, floured poster board patterns (I cut my patterns on parchment, which was easy and worked fine), and sharp paring knife to cut all house pieces on cookie sheet, making sure to leave at least 1¼ inches between pieces because dough will expand slightly during baking. Wrap and reserve trimmings in refrigerator. Combine and use trimmings as necessary to complete house and other decorative pieces. Cut and bake large pieces and small pieces separately.
Chill for 10 minutes before baking if the dough seems really soft after you cut it. This will discourage too much spreading/warping of the shapes you cut.
Bake 25 to 30 minutes, until pieces are firm to the touch. Do not overbake; pieces will be too crisp to trim to proper size.
Remove cookie sheet from oven. While house pieces are still warm, place poster-board patterns on top and use them as guides to trim shapes to match if necessary. Cool pieces completely before attempting to assemble the house.
This makes enough dough for two gingerbread houses. Happy insanity.
Recipe by The Domestic Front at https://www.thedomesticfront.com/you-want-me-to-do-what-gingerbread-bungalow/