Preheat oven to 375 degrees F (190 degrees C). Grease a 9x13 inch baking pan.
In a medium bowl, cream together the butter, sugars, egg, and vanilla until light and fluffy. In a separate bowl, mix together the flour, baking soda, and salt. Gradually add the flour mixture to the butter mixture, stirring until combined. Stir in the butterscotch chips.
Press the dough into the prepared pan. Bake for 20 to 25 minutes, or until lightly browned. Allow to cool before cutting into bars.
Interesting Facts
Butterscotch is a type of confectionery made with brown sugar and butter.
It is believed that butterscotch originated in England sometime in the 19th century.
Butterscotch bars are a popular treat in the United States.