Prepare the baking sheets: Preheat the oven to 350°F and line a few baking sheets with parchment paper. Set aside.
Brown the butter: Use this post for guidance. Add the butter to a light-colored skillet or saucepan over medium heat. Melt the butter, stirring frequently. Continue cooking as it foams and sizzles until the milk solids at the bottom of the pan turn golden brown and the butter smells nutty. Immediately pour the browned butter, including all of the browned bits from the bottom of the pan, into a large mixing bowl. Let cool on the counter for 10-15 minutes Start Timer. The butter should still be liquid but no longer piping hot. 1 cup unsalted butter
Add the sugars: Add the dark brown sugar and granulated sugar to the browned butter. Whisk until well combined. It will look a bit sandy; that’s ok.
1 cup packed dark brown sugar, 2/3 cup granulated sugar
Add the wet ingredients: Whisk in the pumpkin butter, egg, egg yolk, and vanilla until smooth and combined.
1/3 cup pumpkin butter, 1 large egg, 1 large egg yolk, 2 tsp. vanilla extract
Add the dry ingredients: In a separate medium bowl, whisk together the flour, baking powder, baking soda, pumpkin pie spice, cornstarch, and salt. Add the dry ingredients to the wet ingredients and fold together just until a soft cookie dough forms. Do not overmix. Allow the dough to sit at room temperature for 5-10 minutes Start Timer. The dough will thicken as the flour hydrates and the browned butter continues to cool.
2⅔ cups all-purpose flour, 1 tsp. baking powder, 1 tsp. baking soda, 1 tsp. pumpkin pie spice, 1 tsp. cornstarch, 1 tsp. kosher salt
Make cinnamon sugar: In a small bowl, stir together the granulated sugar and cinnamon.
1/4 cup granulated sugar, 1 tsp. ground cinnamon
Scoop and roll: Using a 2-Tbsp. cookie scoop, portion the dough and roll into balls. Roll each cookie dough ball in the cinnamon sugar until evenly coated. Arrange on the prepared baking sheets, leaving about 2 inches between each cookie. I usually bake ~6-8 cookies at a time.
Bake: Bake for 8-10 minutes Start Timer, or until the edges are set but the centers still look slightly soft and underbaked. Do not overbake. The cookies will continue to set as they cool. Immediately after removing the cookies from the oven, use a large round cookie cutter or glass to gently scoot the cookies into perfectly round shapes. Let cool on the baking sheet for 3-5 minutes Start Timer, then transfer to a wire cooling rack to cool completely.
Make the glaze: Once the cookies have cooled, whisk together the powdered sugar, 1 tablespoon milk, vanilla, corn syrup, pumpkin pie spice, and salt. Add additional milk a little at a time until the glaze is thick but drizzleable. If the glaze becomes too thin, add a little more powdered sugar.
1 cup powdered sugar, 1-2 Tbsp. whole milk, 1/2 tsp. vanilla extract, 1 tsp. light corn syrup, Pinch of pumpkin pie spice, Pinch of kosher salt
Glaze and serve: Drizzle the glaze over the cooled cookies. Allow the glaze to set, then enjoy!