Line 2 large baking sheets with parchment paper and set them aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugar on medium-high speed until light and fluffy, at least 2 minutes.
1 cup unsalted butter, 1 cup granulated sugar
Add the egg, pumpkin puree, and vanilla. Mix to combine. Make sure to scrape down the sides of the bowl as needed.
1 large egg, ¼ cup pumpkin puree, 1 tablespoon pure vanilla extract
In a separate medium bowl, whisk together the flour, baking powder, and pumpkin pie spice.
3½ cups all-purpose flour, 1½ teaspoons baking powder, 1½ teaspoons pumpkin pie spice
With the mixer on low speed, slowly add the dry ingredients. Mix just until the dry ingredients are incorporated—you don’t want to overmix.
Turn the dough out onto a lightly floured surface and roll it out to ¼-inch thick. Cut out your desired shape using cookie cutters (I’m using a 2-inch pumpkin cookie cutter).
Transfer the cookies to the prepared baking sheets, making sure to place them at least 2 inches apart.
Place the cookies in the refrigerator or freezer (either will work) to chill for 20 minutes.
While the dough chills, preheat oven to 375°F.
Bake the chilled cookies for 12-15 minutes, or until the edges and bottoms are just barely golden brown.
Allow the cookies to cool completely on the tray.
Decorate them as desired before serving.