In a medium saucepan over medium heat, melt the unsalted butter, stirring constantly until it turns a deep amber color, about 5-7 minutes. Remove from heat and let cool slightly, then transfer to the fridge for about 20 minutes to solidify.

Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a medium bowl, whisk together the all-purpose flour, baking soda, baking powder, salt, pumpkin pie spice, and cinnamon. Set aside.

In a large bowl, combine the chilled brown butter with dark brown sugar until crumbly, then whisk in the egg yolk, maple syrup, vanilla extract, and pumpkin puree until smooth.

Gently fold the dry ingredients into the wet ingredients until just combined. If too thin, cover and chill for an additional 15-20 minutes.

Mix brown sugar, granulated sugar, and cinnamon in a small bowl. Scoop about 2 oz of dough, roll into a ball, and coat in sugar mixture.

Place cookie balls on the prepared baking sheet and bake for 12-15 minutes until edges are slightly darkened and centers look puffy.

Let cookies rest on the baking sheet for 5 minutes before transferring to a cooling rack.