Preheat oven to 350 degrees F.

Cream together butter and sugars until blended and fluffy. (You can do this on medium-low speed of an electric mixer for 2-3 minutes or by hand.)

Add egg and vanilla, and mix again until smooth. Stir in flour, baking soda, salt, and coats until dry ingredients are incorporated. Stir in butterscotch chips.

With a medium cookie disher or tablespoon, scoop balls of dough and place them about 1 1/2″ apart on a cookie sheet lined with a silicone mat or parchment paper. Bake for 12-15 minutes, until edges are starting to brown. Allow to cool for a few minutes on baking sheet, then transfer to a wire rack to cool completely.