Preparation Steps

• To brown the butter, melt the butter in a large saucepan on medium heat. Once melted, begin stirring occasionally. The butter will begin to crackle and pop and foam will form at the top. Continue stirring. Once sizzling sound stops, continue stirring often until golden brown bits begin to collect on the bottom of the pan. The butter will smell slightly nutty and aromatic. Remove from heat. Pour the butter and the dark bits of milk solids into a large bowl and chill for 30 minutes. Do not let the butter solidify. It should be cool to the touch but still mostly liquid.
• Meanwhile, place the pumpkin puree on a plate lined with two layers of paper towels. Top with a second paper towel and blot the pumpkin to help remove some of the moisture. Set aside.
• Once the brown butter is cool, add the butter to the bowl of a stand mixer fitted with the paddle attachment along with the granulated sugar and brown sugar. Mix on medium low speed for 1 minute until combined. The mixture will resemble wet sand.
• Add the pumpkin puree, egg yolk, molasses and vanilla. Mix to combine, about 30 seconds. Scrape down the sides of the bowl.
• In a separate bowl, whisk together the flour, baking soda, cream of tartar, spices and salt.
• Add the dry ingredients to the butter and pumpkin mixture. Mix until a few streaks of flour remain. Do not over mix. Place the bowl in the refrigerator, uncovered, for 30 minutes to firm up the dough.
• While the dough is chilling, preheat the oven to 350°F. Line to baking sheets with parchment paper. Set aside.
• In a shallow bowl, whisk together the remaining granulated sugar and cinnamon for rolling the cookie dough.
• Once the dough is set, remove the bowl from the refrigerator and use a large cookie scoop to divide the dough into approximately 2-ounce portions. Do not roll the cookie dough into balls between your palms. Place it in the bowl of cinnamon sugar and use your hands to coat all sides of the dough.
• Place the cookie dough on the prepared baking sheets, leaving 2 to 3 inches between each cookie. The dough will spread in the oven.
• Bake on the center rack of the oven for 9 to 10 minutes or until the edges are set and the tops begin to crack. Do not over bake or the cookies will be dry.
• Remove the cookies from the oven and allow to cool on the pan for 5 to 10 minutes before carefully transferring to a wire rack. Sprinkle with more cinnamon sugar if desired.