Cream the butter and brown sugar in a large bowl until light and fluffy.
Whisk the molasses and egg into the butter mixture until fully emulsified.
Combine the dry ingredients including flour, baking soda, ginger, cinnamon, and salt in a separate container.
Gradually add the dry ingredients to the wet mixture, stirring slowly until a thick dough forms.
Wrap the dough in plastic wrap and chill in the refrigerator for at least 2 hours.
Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper.
Roll out the chilled dough on a floured surface to your desired thickness.
Cut into shapes using cookie cutters and place on prepared baking sheets.
Bake for 10 minutes or until edges are set.
Cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.