Preheat oven to 375°F. Line two baking sheets with parchment paper. Set aside.
Using a large stand mixer or a large bowl with hand mixer, cream the butter on its own for a minute. Add the granulated sugar and brown sugar and beat until combined. Add eggs and vanilla, beat for one minute.
In a separate large bowl, whisk together flour, baking soda, cinnamon, and salt.
Slowly add the dry mixture (flour mix) to the wet mixture (butter mixture) and beat until combined.
Using a wooden spoon or a spatula, stir in the rolled oats and butterscotch chips.
Spoon cookie batter by the teaspoonful onto the prepared baking sheets lined with parchment paper. Please each drop about 2 inches apart, as the dough will spread a bit.
Bake at 375°F for 8 to 10 minutes, just until the tops and edges start to turn a golden brown. Remove and cool on cooking racks for 5 minutes before devouring.
Notes
Feel free to add more rolled oats for a chunkier, oatmeal-like cookie. You can also leave them out completely.