In a stand mixer or medium bowl with a hand mixer cream together softened butter, granulated sugar, and brown sugar. When fluffy add egg, vanilla, and pumpkin. Mix on low until well combined.
In large mixing bowl whisk together flour, cinnamon, nutmeg, ground cloves, all spice, cream of tartar, baking soda, xanthan gum, and salt.
Create a well in the middle of the dry ingredients. Pour wet ingredients (pumpkin mix) in the well. Gently fold dry and wet ingredients together until all the way combined. Be careful not to over stir. Chill in fridge for 30min.
PREHEAT OVEN TO 350.