Preheat the oven to 350F. Line 2 baking sheets with parchment paper or silpat liners.
In the bowl of a stand mixer fitted with the paddle attachment, mix together the granulated sugar, brown sugar, pumpkin and oil on medium speed for 1-2 minutes until incorporated. Add the egg and vanilla and mix to combine.
In a medium bowl, mix together the gluten-free flour, pumpkin pie spice, baking powder, baking soda, and salt. Add the dry ingredients to the wet ingredients in the stand mixer and mix on low speed to to fully combine. Stir in the chocolate chips.
Using a cookie scoop, scoop 1 ½ tablespoon-sized mounds onto the baking sheets. Bake for 14-16 minutes, until set. (Do not under-bake or the cookies will be too wet.) Like most gluten-free cookies, these are best eaten the day they are made, although leftovers can be stored in an airtight container. Enjoy!