Preheat your oven to 350°F (180°C) and line your baking trays with parchment paper.

Melt the cold unsalted butter in a stainless steel pan over medium heat until it turns golden with brown bits forming.

Blot the pumpkin puree on a plate with paper towels to remove excess moisture.

Whisk the cooled brown butter with granulated and light brown sugars in a mixing bowl for about 1 minute. Add egg yolks, vanilla extract, and the blotted pumpkin puree.

Fold in the all-purpose flour, pumpkin spice, baking soda, and fine sea salt. Stir just until the flour is visible.

Gently mix in the finely chopped chocolate bar or chocolate chips into the dough.

Using a cookie scoop, portion the dough onto the prepared trays, spaced apart. Bake for 9-13 minutes until edges are golden.

Once baked, cool on a wire rack. Optionally, use a cookie cutter to shape still-warm cookies.