Preheat oven to 350°F. Line two baking sheets with parchment paper and set aside.
In a large mixing bowl, whisk the melted butter, granulated sugar, and brown sugar together. Whisk in the egg yolk, pumpkin, and vanilla extract until smooth.
Add the flour, cream of tartar, baking soda, baking powder, salt, spices to the butter/sugar mixture. Mix together with a rubber spatula or wooden smooth until a dough forms.
Use a medium cookie scoop to scoop out 2 tbsp of dough and roll into balls. Mix together the remaining ½ cup of granulated sugar and 1 teaspoon of cinnamon. Roll each of the cookie dough balls in the cinnamon-sugar mixture and arrange onto the prepared baking sheets, about 2 inches apart.
Bake for 9-11 minutes or until the edges appear set and the centers are still soft.
Allow cookies to cool on the baking sheets for 5 minutes before transferring to a wire rack to cool completely.
Store cookies in an air tight container at room temperature for up to 1 week.