Preheat oven to 350 F. Line a baking sheet with parchment paper or a silicone baking mat.
In a large bowl beat the butter on medium speed for 30 seconds.
Add sugar, baking powder,baking soda, salt, and pumpkin pie spice. Beat until combined.
Beat in the egg and vanilla until combined.
Mix in pumpkin.
Stir in flour until incorporated.
Drop medium cookie scoops (1.5 tablespoons) of dough 2 inches apart on prepared baking sheet.
Bake for 10-12 minutes or until tops are set.
To make the icing, combine the butter, cream, brown sugar, salt, and cinnamon in a medium saucepan over medium heat.
Heat mixture until it comes to a boil, stirring frequently.
Once it comes to a boil, allow it to boil for one minute.
Remove from heat.
Whisk in the vanilla and powdered sugar until smooth and incorporated. Be sure to sift the powdered sugar before adding it to avoid lumps in the frosting.