Preheat your oven to 350°F.
In a medium bowl, whisk together oats, flour, baking soda, cinnamon, and salt.
In a large bowl, cream together butter, brown sugar, and granulated sugar until light and fluffy, about 2-3 minutes. Beat in vanilla and eggs one at a time.
Gradually add dry ingredients to wet mixture, stirring until just combined. Fold in butterscotch chips and nuts if using.
Drop rounded tablespoons of dough onto a baking sheet, spaced about 2 inches apart.
Bake for 10-12 minutes until edges are golden and centers are soft.
Cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.