Thoroughly mix together the flour, soda, salt and spices.
In a saucepan melt the shortening. Let cool slightly and add the sugar and molasses. Add eggs when cool.
Add the oil mixture to your mixing bowl fitted with the paddle attachment. Add 4 cups of the flour. Mix together thoroughly. Add remaining flour a little at a time to make a stiff dough.
Roll out the dough on the back of greased cookie sheets to about 1/8th inch thick. Lay your pattern pieces on top and cut out with a knife or pizza cutter. Place cookie sheets in the refrigerator for 15 minutes.
Preheat oven to 350 degrees. Bake for about 6 minutes for smaller pieces and up to 12 for the larger pieces like the roof. Let set on the cookie sheet for a few minutes before removing to a wire rack to cool. Let pieces dry overnight before assembling.
Royal Icing
Beat all ingredients at low speed for 7-10 minutes (10-12 minutes at high speed for portable mixer) until icing forms peaks. Keep icing covered with a damp cloth when not in use.
Note: Royal icing should have good body and be moderately stiff: It will not create a lasting bond if too runny and soft. For snow, I sometimes add a few drops of Karo Syrup to thin it just a little for a softer look.
Recipe by Recipes Food and Cooking at https://recipesfoodandcooking.com/2014/12/15/gingerbread-christmas-tree/