Brown the butter. To brown, add the two sticks of butter to a small saucepan or skillet over medium-low heat. Melt until the butter begins sizzling and foaming, just a few minutes. Stir constantly with a spatula until the milk solids turn dark brown and smell like caramel. Transfer to a large mixing bowl and set aside to cool for 15-20 minutes.

In another medium mixing bowl, combine the flour, salt, baking soda, and pumpkin pie spice. Set aside.

Once the butter has cooled, pour in the blotted pumpkin puree, brown sugar (break up any clumps), maple syrup, egg yolk, sourdough discard, and vanilla extract and whisk together.

Dump the dry ingredients into the bowl of wet ingredients and use a spatula to mix just until the flour is hydrated.

Cover and chill in the refrigerator for at least four hours and up to a few days to fully hydrate the flour, let the flavors meld, and make portioning out easier.

Preheat the oven to 350ºF (177ºC) and line two baking sheets with parchment paper or a silicone baking mat.In a small bowl, combine the granulated sugar and ½ tsp of reserved pumpkin pie spice or cinnamon.Use a large cookie scoop or spoon to portion out 20 cookies (about 45g each), roll into balls in the sugar, and place onto the baking sheets with a couple of inches in between them. I like to sprinkle more sugar on top before baking as well.

Bake one sheet of cookies at a time in the middle rack for 12-14 minutes or until the edges set and begin to brown.The cookies will puff up some during baking. While hot out of the oven, use a spatula or the palm of your hand to press down on the cookies to flatten them. This will help keep them chewy!Transfer to wire racks to cool completely.