Cookies
1-In a stand mixer or large bowl,: In a stand mixer or large bowl, cream together the softened butter, pumpkin puree, brown sugar, granulated sugar, and vanilla until the mixture is light and fluffy.
2-In a separate large bowl, whisk together: In a separate large bowl, whisk together the all-purpose flour, baking powder, pumpkin pie spice, cornstarch, and salt.
3-Gradually add the dry ingredients to the: Gradually add the dry ingredients to the wet ingredients bowl, mixing on low speed until just combined (don’t over-mix).
4-Cover the bowl and place it in: Cover the bowl and place it in the fridge for 30 minutes or overnight.
5-Preheat the oven to 350 °F (177: Preheat the oven to 350 °F (177 °C).
6-Scoop 2-inch balls of dough out with: Scoop 2-inch balls of dough out with a medium cookie scooper or a large spoon. Press down to flatten the dough balls into disks. While baking, the dough will not spread out much so you need to form it into a cookie shape beforehand. Arrange them a couple of inches apart on a parchment-lined baking sheet.
7-Bake on the center rack for 10-12: Bake on the center rack for 10-12 minutes. Let them cool down completely on the baking sheet.

Cinnamon Frosting
8-In a medium bowl, use an electric: In a medium bowl, use an electric mixer or a stand mixer with the whisk attachment to whip together all the ingredients until fully combined. If preparing in advance, cover with plastic wrap and refrigerate until ready to use.
9-Spoon icing into a piping bag fitted: Spoon icing into a piping bag fitted with the Wilton Piping Tip #2A. Pipe the cinnamon frosting on top of the cooled cookies in a swirl, starting from the middle and moving outwards. Sprinkle pumpkin pie spice on top, and enjoy!