Preheat your oven to 350°F (175°C).
In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.
In a large bowl, cream together the softened butter, granulated sugar, brown sugar, and vanilla extract until light and fluffy.
Add the eggs one at a time, mixing well after each addition.
Gradually add the flour mixture to the butter mixture, mixing until just combined.
Fold in the butterscotch chips until evenly distributed.
Drop rounded tablespoons of dough onto ungreased baking sheets, spacing them about 2 inches apart.
Bake for 10-12 minutes, or until the edges are lightly golden. The centers may look slightly underbaked; they will firm up as they cool.
Allow the cookies to cool on the baking sheets for 5 minutes before transferring them to wire racks to cool completely.