• Preheat the oven to 375°F. Line two large baking sheets with parchment paper or silicone baking mats. Set aside.
• Cream together the butter, brown sugar and granulated sugar in a large bowl or the bowl of a stand mixer, for 2 to 3 minutes or until creamy and combined.
  ¾ cup unsalted butter, 1 cup dark brown sugar, ½ cup granulated sugar
• Add the egg and vanilla and beat in until combined. Mix in the pumpkin puree.
  1 large egg, 1 teaspoon vanilla extract, 1 cup pumpkin puree
• In a medium bowl, whisk together all purpose flour, old fashioned oats, pumpkin pie spice, cornstarch, baking soda, baking powder and salt.
  2 cups all purpose flour, 1¼ cups old fashioned oats, 2 teaspoons pumpkin pie spice, 1 teaspoon cornstarch, 1 teaspoon baking soda, ½ teaspoon baking powder, ½ teaspoon fine sea salt
• Add the dry ingredients to the pumpkin mixture and stir just until combined.
• Use a cookie scoop (1 ½ tablespoons) to scoop dough and place 2 inches apart on the prepared baking sheets.
• Bake cookies for 9 to 11 minutes until puffed up and no longer glossy on top. Let cookies cool for 10 minutes on the sheet tray before transferring to a wire rack to cool completely.

Cookie Icing

• Whisk together the powdered sugar, milk and vanilla extract in a small, shallow bowl until smooth.
  1½ cups powdered sugar, 2 tablespoons whole milk, ¼ teaspoon vanilla extract
• Dip the cookies in the icing or drizzle on top. Return cookies to the wire rack and let sit for 10 minutes so the icing can set.