1. Melt the butter in a saucepan over medium heat and cook until it turns golden brown and smells nutty. Remove from the heat and let it cool for 10 to 15 minutes.

2. Blot the pumpkin puree with paper towels to remove excess moisture.

3. In a large bowl, whisk together the browned butter, brown sugar, and 1/2 cup granulated sugar until smooth.

4. Add the egg yolk, vanilla extract, and blotted pumpkin puree, then mix until fully combined.

5. In a separate bowl, whisk together the flour, cream of tartar, baking soda, salt, cinnamon, and pumpkin pie spice.

6. Add the dry ingredients to the wet ingredients and stir just until a soft dough forms.

7. Cover the dough and chill for 30 minutes.

8. Preheat the oven to 350°F and line baking sheets with parchment paper.

9. In a small bowl, mix 1/4 cup granulated sugar with 1 1/2 teaspoons cinnamon.

10. Scoop the dough into balls and roll each one in the cinnamon sugar mixture.

11. Arrange the dough balls on the prepared baking sheets with space between them.

12. Bake for 10 to 12 minutes, until the edges are set and the centers are still soft.

13. Let the cookies cool on the pan for 5 minutes, then transfer them to a wire rack.