Oatmeal Butterscotch Cookies

butter, softened 3/4 cup sugar 3/4 cup brown sugar 2 large eggs 1 tsp vanilla extract 1 1/4 cups all-purpose flour 1 tsp baking soda 1/2 tsp ground cinnamon 3/4 tsp salt 3 cups rolled oats 1 1/2 cups butterscotch chips