1. Melt the butter in a saucepan over medium heat, stirring until it foams and turns golden brown with a nutty aroma. Remove from heat and let it cool slightly.

2. In a large mixing bowl, combine browned butter, brown sugar, and granulated sugar. Mix until smooth.

3. Add pumpkin puree, egg yolk, and vanilla extract. Stir until fully blended.

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

5. Slowly add the dry ingredients to the wet ingredients. Mix until just combined.

6. Cover and refrigerate dough for 30–60 minutes.

7. In a small bowl, mix ¼ cup granulated sugar and 1 teaspoon cinnamon for rolling.

8. Scoop 1.5-tablespoon portions of chilled dough, roll into balls, then coat in the cinnamon sugar mixture.

9. Place balls on a parchment-lined baking sheet, spacing them out.

10. Bake at 350°F (175°C) for 9–11 minutes, or until edges are set and centers look slightly underdone.

11. Cool on the tray for 5 minutes, then transfer to a wire rack to cool completely.