In a medium mixing bowl, combine flour, pumpkin pie spice, cinnamon, salt, baking powder and baking soda. Whisk to thoroughly combine, then set aside.
In a large mixing bowl, cream butter with sugars using an electric mixer until light and fluffy, about 3 minutes. Then add egg and beat to combine.
Add vanilla and mix to combine, then add pumpkin and beat until smooth and uniform, about 1 minute.
Add dry ingredients to the pumpkin mixture and beat until just combined. Scrape bottom and sides of bowl with a rubber spatula, then mix again just to combine.
Line baking sheet with silicone mat or parchment paper.
Using a cookie scoop, portion out dough onto prepared baking sheet. Refrigerate dough for 30 minutes.
Preheat oven to 350°F / 325°F with convection / 180°C / Gas mark 4.
Remove tray of cookie dough from refrigerator and place in preheated oven. Bake for 12 - 15 minutes (time varies by oven) until golden brown around the edges.
Remove from the oven and let cookies cool on baking sheet for 5 minutes before removing to a cooling rack to cool completely.