Preheat your oven to 350 degrees and line your baking dish with parchment paper.
Using a standing mixer, cream together the butter and sugar
Add in the eggs, pumpkin pure, and vanilla extract
Mix until combined
In a large bowl, combine the flour, pumpkin pie spice, baking powder and salt. Using a whisk mix until combined
Gradually add in the flour mixture into wet mixture until combined
Scoop batter into parchment paper lined baking dish
Spray pam spray on your hand so that you can flatten down the batter into the pan with getting the batter on your hands
Place into the oven and bake for 20 minutes
Once baked, place onto a wire rack to cool to room temperature
Using the standing mixer, combine the butter, vanilla and cream cheese and mix until combined
Add in the cinnamon and powder sugar and mix until combined and fluffy
Scoop the frosting onto the cooled cookie and smooth it out.
Sprinkle the harvest sprinkles onto the frosting and place into the fridge for an hour for the frosting to harden
Cut into bars and enjoy!