Preheat the oven to 400 degrees fahrenheit. Line 2 baking sheets with parchment paper and set aside.
In a stand mixer fitted with the paddle attachment, beat together both sugars with the butter until pale and fluffy, about 3-4 minutes.
Add in the eggs and vanilla extract and beat until combined.
In a separate bowl combine the oats, baking powder, baking soda, salt, and flour. Whisk to combine.
Add the dry to the wet and mix until just combined, being careful to not overmix. Fold in the butterscotch chips by hand.
Roll out golf-ball sized dough balls and place 2 inches apart on the prepared baking sheet. Bake for 8-10 minutes or until just lightly golden brown. Watch carefully to avoid over-baking; slightly under-baked cookies make the best chewy cookies!