Preheat oven to 375°F.
In a medium-sized bowl, mix flour, baking soda, cinnamon and salt. Stir in oats.
In bowl of electric mixer, cream softened butter, granulated sugar and brown sugar on medium-high speed until pale and fluffy (about 5 minutes).
Add eggs and vanilla. Mix until well incorporated.
Add flour-oat mixture, mixing on low speed.
Add butterscotch chips. Mix in by hand.
Scoop out in 1 Tablespoon portions either with a cookie scoop or a spoon. Place on ungreased baking sheet.
Bake at 375°F for 7-8 minutes for a chewier cookie or 9-10 minutes for a crispier cookie.
Cool 2 minutes before removing to wire rack to cool completely.
Store tightly covered up to 3 days at room temperature or freeze for longer storage.