1. Brown the butter in a light-colored saucepan over medium heat until golden brown flecks form and aroma is nutty, then cool 10–15 minutes.

2. Whisk cooled brown butter with brown sugar and granulated sugar until smooth, then add pumpkin purée, vanilla extract, and egg yolk until well combined.

3. In a separate bowl, whisk flour, baking soda, cream of tartar, salt, cinnamon, nutmeg, and cloves; fold into wet ingredients until just combined, then chill dough 30–45 minutes.

4. Preheat oven to 350°F (175°C) and line baking sheets with parchment. Roll chilled dough into 1½ tablespoon balls, coat in cinnamon-sugar, and place 2 inches apart.

5. Bake cookies 9–11 minutes until edges are set and centers remain soft, then let rest on baking sheet 5 minutes before transferring to a wire rack.

6. Cool completely or serve warm for soft, chewy centers and gently crisp edges.