In a medium bowl, mix butter and sugar for about 2 minutes
Add the pumpkin and egg.
Slowing add flour, baking soda and cinnamon into pumpkin mixture. Fold flour mix with pumpkin mix until fully combined.
Add a large tablespoon of batter onto prepared baking sheet, each about 2 inches apart.
Bake for 10-12 minutes.
Allow cookies to cool 5 minutes before carefully removing from the parchment paper. Place on cooling rack.
Once the cookies are fully cooled, frost with brown sugar icing.
BROWN SUGAR ICING
In a medium bowl, add your hot melted butter and brown sugar. Stir together to allow the sugar to dissolve. Allow the mixture to cool for 10-15 minutes.
Beat in your vanilla extract, milk and 1/2 cup powdered sugar. Continue to add in remaining powdered sugar, 1/2 cup at a time. If frosting is a little thick, add milk. If it's a little thin, add powdered sugar until it reaches the desired consistency.