Preheat the oven to 350°F. Line two baking sheets with parchment paper.
Brown the butter: Place the butter in a light-colored saucepan over medium heat. Cook, stirring frequently, as it melts, foams, and turns amber-colored with dark specks at the bottom — about 5–7 minutes. Don't walk away; it burns fast. The smell will shift from milky to nutty and toasty. Pour into a heatproof bowl and let cool for 10 minutes until it's warm but no longer hot.
Mix the dry ingredients: In a medium bowl, whisk together the flour, baking soda, cinnamon, ginger, nutmeg, cloves, and salt. The aroma of cinnamon and ginger will already fill your kitchen.
Combine the wet ingredients: Add the brown sugar and granulated sugar to the cooled brown butter. Whisk until smooth and thick — it should feel like a thick caramel. Add the egg, vanilla, and pumpkin puree, and whisk until fully combined and glossy. The batter will look silky and smell like warm spices and butter.
Fold it all together: Pour the dry ingredients into the wet ingredients. Fold gently with a rubber spatula until just a few streaks of flour remain. Add the dark chocolate chips and fold until evenly distributed. The dough will be soft and slightly sticky — that's perfect.
Scoop and bake: Scoop rounded tablespoons (about 1.5 tbsp each) onto the prepared baking sheets, spacing them 2 inches apart. Bake for 11–13 minutes, rotating the pans halfway through. The edges should be set and lightly golden, but the centers will look slightly puffed and soft. Your kitchen will smell like a cozy bakery — cinnamon, ginger, toasted butter, and chocolate.
Cool and enjoy: Let the cookies cool on the baking sheet for 5 minutes — they'll be fragile and soft. The centers will continue to set as they cool. Transfer to a wire rack to cool completely.