Step 1: Brown the butter in a medium saucepan over medium heat, stirring constantly until it turns amber brown and smells nutty. Pour into a large bowl and let it cool until it reaches a soft solid consistency.
Step 2: Place the pumpkin puree on several layers of paper towels. Press firmly with more paper towels to remove as much moisture as possible until you are left with about 1/3 cup of concentrated puree.
Step 3: Cream the cooled browned butter with the dark brown sugar and granulated sugar using a hand mixer or stand mixer until light and fluffy.
Step 4: Beat in the egg yolk, vanilla extract, and the blotted pumpkin puree until well combined.
Step 5: In a separate bowl, whisk together the flour, baking soda, salt, cinnamon, ginger, nutmeg, and cloves.
Step 6: Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined. Do not overmix.
Step 7: Cover the dough and refrigerate for at least 2 hours, or overnight for the best flavor development.
Step 8: Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper. Scoop rounded tablespoons of dough onto the sheets.
Step 9: Bake for 10-12 minutes or until the edges are set. Let the pumpkin brown butter cookies cool on the baking sheet for 10 minutes before transferring to a wire rack.