Preheat your oven to 375 F. Line rimmed baking sheets with unbleached parchment paper and set them aside.
In a large bowl, place the flour, xanthan gum, baking soda, baking powder, salt, cinnamon, pumpkin pie spice, granulated sugar and brown sugar, and whisk well, eliminating any lumps. Add the granola and mix again.
Add the oil, vanilla, butter, eggs, and pumpkin, mixing well after each addition. The batter will be thick and stiff, but not quite as stiff as you would expect regular cookie dough to be.
Divide the dough into thirty-six equal portions. This works best with a small, spring-loaded ice cream scoop, but can easily be done with two small spoons. Place the portions of dough about 1 inch apart on the prepared baking sheets. Place the baking sheets in the freezer for about 10 minutes, until the dough is firm.
Bake the cookies in the center of the oven for 10 to 12 minutes, or until lightly browned around the edges and solid to the touch, rotating the baking sheet once during banking.
Allow to cool on the baking sheet for 5 minutes before transferring the cookies to wire racks to cool completely.
Store the cookies back to back, with small sheets of parchment paper between pairs of cookies, in airtight containers either on the counter or in the refrigerator. Refrigeration tends to dry out baked goods, but these cookies are moist enough that they can stand up to it well for about 5 days. They will last 2 days at room temperature, and can be frozen for about 2 months