Whisk the flour, baking powder, cinnamon, allspice, ginger, nutmeg, and salt together in a medium bowl. Set aside.

In a large bowl using a handheld or a stand mixer fitted with a paddle attachment, beat the butter and brown sugar together on high speed until completely smooth and creamy, about 3 minutes. (Here’s a helpful tutorial if you need guidance on how to cream butter and sugar.) Add the egg and vanilla, and beat on high speed until combined, about 1 minute. Scrape down the sides and bottom of the bowl and beat again as needed to combine.

Add the dry ingredients to the wet ingredients and mix on low speed until combined. Dough will be a bit soft. If the dough seems too soft and sticky for rolling, add more flour, 1 Tablespoon at a time, beating well after each addition.

Divide the dough in half. Place each portion onto a piece of lightly floured parchment paper or a lightly floured silicone baking mat. With a lightly floured rolling pin, roll the dough out to about 1/4-inch thickness. Use more flour if the dough seems too sticky. The rolled-out dough can be any shape, as long as it is evenly 1/4-inch thick.

Lightly dust one of the rolled-out doughs with flour. Place a piece of parchment on top. (This prevents sticking.) Place the 2nd rolled-out dough on top. Cover with plastic wrap or aluminum foil, then refrigerate for at least 1–2 hours, or up to 2 days.

Once chilled, preheat oven to 350°F (177°C). Line large baking sheets with parchment paper or silicone baking mats. Carefully remove the top dough piece from the refrigerator. If it’s sticking to the bottom, run your hand under it to help remove it. Using a cookie cutter, cut the dough into shapes. Re-roll the dough scraps and continue cutting until all is used. Repeat with 2nd piece of dough. (Note: It doesn’t seem like a lot of dough, but you get a lot of cookies from the dough scraps you re-roll.)

Arrange cookies on baking sheets 3 inches apart. Bake for 11–12 minutes or until lightly browned around the edges. Allow cookies to cool on the baking sheet for 5–10 minutes, then transfer to a wire rack to cool completely before decorating.

Decorate the cooled cookies with royal icing, cookie buttercream, or easy cookie icing; top with sprinkles, if using. Feel free to tint any of these icings with gel food coloring. For decorating inspiration, my How to Decorate Sugar Cookies tutorial is helpful.

Enjoy cookies right away or wait until the icing sets to serve them. Plain or decorated cookies stay soft for about 5 days when covered tightly at room temperature. For longer storage, cover and refrigerate for up to 10 days. If decorated with cookie buttercream, cover and store decorated cookies at room temperature for 1 day, or in the refrigerator for up to 5 days.