Preheat oven to 375 degrees F. Line two baking sheets with parchment paper or a silicone baking mat and set aside.
Whisk flour, baking soda, pumpkin spice, cinnamon, nutmeg, and salt in a small bowl. Set aside.
Beat butter, sugar and brown sugar until smooth and creamy. Add egg and vanilla extract. Next, add in pumpkin and mix until combined.
Slowly add in flour mixture. Stir in oats and butterscotch chips.
Drop dough by the tablespoon onto prepared baking sheets. Bake for 10 to 12 minutes or until the cookies are set and golden. Remove cookies from the oven and cool on the baking sheet for 2 minutes. Transfer to a wire rack and cool completely.