Preheat your oven to 350°F (175°C).
In a medium bowl, whisk together flour, baking soda, cream of tartar, salt, cinnamon, and set aside.
In a large bowl, beat together the butter, granulated sugar, brown sugar, and pumpkin puree until smooth and creamy.
Add the egg and vanilla extract. Mix until fully incorporated.
Gradually mix in the dry ingredients until just combined.
In a small bowl, mix the sugar and cinnamon for the topping.
Using a cookie scoop or tablespoon, scoop dough into balls and roll them in the cinnamon-sugar mixture.
Place the cookie dough balls on a lined baking sheet, spacing them about 2 inches apart.
Bake for 10-12 minutes or until the edges are set and the tops look slightly soft.
Remove from the oven and let cool on the baking sheet for 5 minutes before transferring to a wire rack.