In the bowl of a stand mixer fitted with a paddle attachment or a large bowl with an electric hand mixer, cream together the butter with white sugar and brown sugar until light and fluffy. Add the pumpkin puree, egg and vanilla extract. Set aside.
Whisk or sift together the flour, cream of tartar, baking powder, salt and pumpkin pie spice.
Add half of the dry ingredients to the wet ingredients, mix, and then add the rest until it just comes together.
Cover and chill for a minimum of 1 hour or up to overnight.
When ready to bake, preheat the oven to 350°F and line a baking sheet with parchment paper.
Mix sugar coating ingredients, sugar and pumpkin pie spice, in a small bowl.
Using a 1 1/2 tablespoon cookie scoop and drop into the sugar mixture. Place on the prepared cookie sheet. Use the flat bottom of a glass to gently press the dough out to approximately 1/2 inch thick.
Bake for 10-11 minutes or until they just look baked.
Remove and allow to cool. Gently remove to a wire rack to cool.
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