Prep: Preheat oven to 375 F. Line two 18 by 13 with parchment paper, set aside.
Brown butter: Melt the butter in a small saucepan over medium heat. Heat the butter until bubbling subsides and the butter begins to smell nutty, you should see a few browned bits of milk solids on the bottom of the pan. Swirl the pan periodically to prevent milk solids from sticking to the bottom. Combine spices and browned butter in a large mixing bowl. Set aside until the butter has cooled slightly.
113 grams unsalted butter, 3 grams cinnamon, ⅛ teaspoon nutmeg, ⅛ teaspoon ground cloves, ⅛ teaspoon ground allspice
Make cookie dough: Stir the brown sugar, granulated sugar, pumpkin puree, vanilla and sourdough discard into the browned butter mixture until no traces of discard remain. Fold flour, baking powder, baking soda and salt into the rest of the ingredients. Continue mixing until no traces of flour remain.
50 grams granulated sugar, 100 grams brown sugar, 75 grams pumpkin puree, 7 grams vanilla, 56 grams sourdough discard, 160 grams all-purpose flour, ¼ teaspoon baking powder, ¼ teaspoon baking soda, ½ teaspoon salt
Add mix-ins: Fold chocolate chips and pecans into the cookie dough.
162 grams chocolate chips, 82 grams pecans
Portion out cookie dough: Using a 3-tablespoon cookie scoop, portion out cookie dough balls and place them on two parchment-lined baking sheets at least 2 inches apart.
Bake: Lightly flatten the cookie dough using your fingers. Bake the cookies for 11 to 13 minutes or until the tops of the cookies look dry. Let the cookies cool on the baking sheet for 5 minutes before transferring to a wire rack.
Enjoy and store: These cookies are best enjoyed once they have completely cooled. They are delicious warm but are even better the next day! Store any leftover cookies in an airtight container at room temperature for up to 7 days.