In a large bowl, sift together flour, ginger, cinnamon, allspice, baking soda, and salt. Set aside. TIP: scoop flour and level with the back side of a knife.
In a stand mixer fitted with the paddle attachment, cream butter and brown sugar on medium speed until fluffy, about 3 minutes.
Beat in egg, scraping sides of bowl between additions.
Add molasses and vanilla and beat until completely incorporated.
Reduce mixer speed to low and add flour mixture until thoroughly combined, about 30 seconds. Dough should be tender (not dry or crumbly) but not sticky. If sticky, add flour one tablespoon at a time until dough is not tacky to the touch. If dry, add molasses one tablespoon at a time until dough starts pull together.
Roll dough between two pieces of lightly floured parchment paper to desired thickness. TIP: wood dowels or rolling pin rings make this easy!
Chill rolled dough for about 2 hours.
Cut desired shapes and transfer to parchment lined baking sheets. Chill shapes until ready to bake.
Bake until edges just start to brown. 8 minutes for medium cookies 10 minutes for large cookies. Be careful not to over bake. Cookies may become dry if over baked.
Cool for 5 minutes on pans then transfer to wire racks to cool completely.