How to Make It
Line 2 baking sheets with parchment. In a medium bowl, whisk together the flour, cinnamon, nutmeg, and ginger; set aside.
Using an electric mixer, beat the butter and granulated sugar on medium-high until light and fluffy, 2 to 3 minutes. Beat in the egg, then the vanilla and salt.
Reduce mixer speed to low and gradually add the flour mixture, mixing until just combined (do not overmix). Shape into a 1-inch-thick disk, wrap in plastic wrap, and refrigerate for at least 2 hours and up to 3 days.
Heat oven to 350° F. On a floured surface, roll the dough ¼ inch thick. Using lightly floured 2- to 3-inch cookie cutters, cut the dough into shapes, flouring the cutters and rerolling the scraps as necessary. Place the cookies 1 inch apart on the prepared baking sheets. Sprinkle with decorating sugar, if using.
Bake, rotating the baking sheets halfway through, until the edges just begin to brown, 12 to 15 minutes. Let cool slightly on the baking sheets, then transfer to a wire rack to cool completely.