Preheat the oven to 350ºF. Spray a 9x13" baking pan with cooking spray, then line with a piece of parchment paper. Spray the top of the paper with cooking spray as well.
In a large mixing bowl, cream together the butter and sugar using an electric mixer.
Add the vanilla and eggs to the butter mixture. Mix well.
Add the flour, baking powder and salt. Mix well.
Fold in the butterscotch chips.
Spread the cookie dough in the prepared pan.
Bake for 30-35 minutes or until the bars are set in the middle.
Cut while the bars are still warm.
Store any leftovers in an airtight container at room temperature for up to 5 days.
Refer to the article above for more tips and tricks.The calories shown are based on the bars being cut into 15 pieces, with 1 serving being 1 butterscotch bar. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information. The information in the nutrition box are calculated through a program and there is room for error. If you need an accurate count, I recommend running the ingredients through your favorite nutrition calculator.**