Preheat the oven to 350℉ (177℃). Line baking sheet pans with a silicone baking mats or parchment paper sheets.
In a medium mixing bowl, whisk together the all-purpose flour, pumpkin pie spice, baking powder, baking soda, and salt. Set aside.
In the bowl of a stand mixer fitted with a paddle attachment or in a large mixing bowl with an electric hand mixer, cream the unsalted butter, brown sugar, and granulated sugar until light and fluffy. Add the egg and vanilla extract and mix well. Then, add the pumpkin puree and mix until well combined and smooth.
Add the flour mixture to the wet ingredients and mix on low speed until the cookie dough forms. Scrape the sides and bottom of the bowl as needed.
Portion the cookie dough using a large cookie scoop (3 tablespoons) and place the cookie dough on the prepared baking sheet pan, allowing room for spreading.
Bake the cookies for approximately 12 minutes until they are set on the edges and puffed up in the center. Cool the cookies on the pan for 2 minutes and then transfer the cookies to a wire rack to cool completely.