Brown the butter in a light-colored skillet until it is nutty and foamy, then transfer it to a glass bowl and cool in the refrigerator or freezer until no longer warm but still liquid.

Cook pumpkin puree in a small saucepan over medium heat for 10 to 15 minutes to thicken, then cool to room temperature in the fridge.

Preheat the oven to 350°F and line baking sheets with silicone mats or parchment paper.

In a large mixing bowl, combine cooled brown butter, brown sugar, and granulated sugar. Beat with an electric mixer for 3 to 4 minutes until creamy.

Add the egg, egg yolk, and vanilla. Beat until combined.

Add flour, cinnamon, baking soda, salt, allspice, nutmeg, cloves, and cardamom. Beat until no dry flour is visible.

Fold in chopped chocolate with a silicone spatula.

Use a 1.5 tablespoon cookie scoop to portion out dough onto baking sheets about 2 inches apart. Press remaining chocolate into tops of cookies.

Bake for 10 to 12 minutes until edges are golden brown and centers are slightly underbaked. Sprinkle flaky salt on top of warm cookies.

Allow cookies to cool on the baking sheet for 5 minutes, then transfer to a cooling rack.