Preheat oven to 350 degrees.
In a large bowl or electric mixer, blend butter, sugar, and brown sugar. Add eggs and vanilla and beat until creamy and smooth.
In a separate bowl, whisk together flour, baking soda, salt, and cinnamon. Add this dry mixture to the butter/sugar mixture and blend well.
Mix in the oats. Stir in the butterscotch chips.
Roll dough into 1 inch balls and place evenly on a lightly greased cookie sheet (non-stick cooking spray works best).
Bake for 10 minutes or until lightly browning on the edges of the cookies. Place on cooling rack.
If you are going to freeze some of the cookies, wait until they are completely cooled, then place them in an airtight container or freezer grade, sealed plastic bag.
This recipe yields approximately 6 dozen cookies.