Brown the butter: Melt 10 tablespoons of unsalted butter in a medium saucepan over medium heat until golden brown, about 4-6 minutes.

Mix the sugars: Whisk together the warm brown butter with ¾ cup granulated sugar and ¼ cup light brown sugar until glossy.

Combine dry ingredients: In another bowl, whisk together 1 ½ cups all-purpose flour, ¼ teaspoon fine sea salt, ½ teaspoon baking soda, and spices.

Incorporate wet ingredients: Stir in 1 egg yolk and 1 teaspoon vanilla extract, then add ⅓ cup canned pumpkin puree.

Form the dough: Gradually add the dry mixture to the wet ingredients, stirring gently, then fold in ¾ cup semisweet chocolate chips.

Chill the dough: Cover dough with plastic wrap and refrigerate for at least 30 minutes.

Preheat and bake: Preheat oven to 350°F (175°C) and line baking sheets with parchment. Scoop dough into balls and bake for 10-12 minutes.

Cool completely: Let cookies cool on baking sheets for about 5 minutes, then transfer to a wire rack.