Cream butter and brown sugar in the bowl of a stand mixer.
Add the egg, molasses, vinegar, and vanilla extract and mix on medium-low just until combined.
In a separate bowl combine all the dry ingredients.
Add dry ingredients to the wet ingredients and mix just until combined to form a soft dough. Don't overmix.
Cover the bowl and chill in the refrigerator at least three hours or up to overnight. (If you chill overnight, you may need to let the dough sit out for 15 minutes to make it easier to roll out the dough.)
When ready to bake, preheat oven to 350℉.
Divide dough in half. Working with one half at a time, roll out dough to 1/4" thickness on a lightly floured board or counter.
Cut out desired shapes and place on a parchment lined baking sheet 1" apart.
Try to place cookies of approximately the same size together. Larger cookies will take longer to bake. Small cookies need about 6-8 minutes, medium cookies about 8-10 minutes, and large cookies about 10-12 minutes. You'll know they are ready when they spring back lightly when you touch the surface. Be careful not to overbake or they will get tough.
Let cool slightly on the baking sheet, then transfer to a wire rack to cool completely. When cool, you can decorate the cookies.