• In a medium bowl, stir or whisk together the flour, spices, salt, baking powder, and baking soda. Set aside.

Brown the butter

• In a medium saucepan, melt the butter over mecum heat. Continue to cook it, stirring often, until it browns, about 5-7 minutes. The butter has browned when it's a bit darker with brown bits on the bottom of the pan. Set it aside to cool.

Reduce the pumpkin puree

• In another saucepan, add the pumpkin and maple syrup and cook on medium-low heat, stirring constantly to prevent burning, about 7 minutes. Transfer to a bowl to cool.

Make the cookie dough

• To a large mixing bowl, add the cooled pumpkin and the brown butter. Add the ¼ cup granulated sugar and the 1 cup brown sugar, the egg yolk and vanilla and whisk until everything is well-combined and smooth, about a minute.
• Gradually add the dry ingredients and stir with a rubber spatula until the mixture is smooth and there are no more white streaks of flour. Don't overmix.
• Cover the surface of the dough with plastic wrap and refrigerate it for at least 30 minutes.
• Meanwhile, preheat the oven to 350℉/180℃ and line two baking sheets with parchment paper.

Make the cinnamon sugar

• Stir the sugar and cinnamon together in a small bowl.
• Use a small cookie scoop or 2 level tablespoons to scoop the chilled dough. I weighed each dough ball, about 35g / 1.2 ounces each. Then roll into balls between your hands. Then roll each dough ball in the cinnamon sugar, one at a time, to coat well.
• Place the coated dough balls on a baking sheet lined with parchment paper. I fit 9 cookies per sheet about 2 inches (5 cm) apart.
• Flatten the dough balls slightly using the bottom of a glass.
• Bake the pumpkin cookies for 15-18 minutes. I bake them one sheet at a time. Let them on the cookie sheet for about 10 minutes before transferring them to a wire rack to cool completely.
• Enjoy!