In a saucepan over medium heat, melt butter. Stir continuously for 5-8 minutes until browned and a nutty aroma develops. Remove from heat and transfer to a glass container to cool for 20 minutes.

In a large bowl, whisk together dark brown sugar and browned butter until combined. Add egg yolk, vanilla, maple syrup, and pumpkin puree, whisking until smooth.

In a separate bowl, whisk together flour, baking soda, baking powder, cinnamon, pumpkin pie spice, nutmeg, and salt.

Fold the dry ingredients into the wet ingredients using a spatula until just combined. The dough will be very soft.

In a small bowl, mix together brown sugar, white sugar, and cinnamon for coating.

Roll the dough into 12 even balls. Coat each ball in the cinnamon sugar mixture.

Place 6 cookies on a baking sheet and bake at 350°F for 10-12 minutes, until the edges are darkened and the centers have puffed.

Let the cookies sit on the baking tray for 5 minutes, then transfer to a cooling rack.