Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper and set aside.
In a medium bowl, whisk together the gluten-free flour blend, baking soda, baking powder, salt, and pumpkin pie spice. Set aside.
In a large bowl, mix together melted butter, pumpkin, brown sugar, molasses, and vanilla. Then gradually add in the dry ingredients to the wet ingredients, mixing thoroughly until combined.
Spoon 1.5 tablespoon sized balls of dough onto parchment lined baking sheets, leaving about 2 inches in between each dough ball. I typically use 2 baking sheets.
Bake at 350°F (175°C) for 8-10 minutes or until edges and bottom of cookies are slightly browned.
Let cool on the baking sheet for 5 minutes before transferring to a wire cooling rack to finish cooling.