In a medium bowl, whisk together flour, salt, baking soda, cream of tartar and pumpkin pie spice. In a large bowl, using either a hand or stand mixer beat softened butter with both granulated and brown sugar and pumpkin puree until creamy.
Add in egg and vanilla extract, beat until smooth. Add the flour mixture in three separate additions, beating after each addition until fully incorporated. Cover and refrigerate for at least one hour.
Preheat oven to 350 F. In a small bowl, combine granulated sugar and ground cinnamon. Roll cookie dough into balls and roll each in the cinnamon sugar mixture. Place cookies 2-inches apart onto ungreased baking sheets. Bake for 10-12 minutes.
