Butterscotch Cookie Bars

These are delcious bar cookies-different than anything you've tasted before.
 1 bag butterscotch chips
  1/2 cup butter
 4 eggs
 1 teaspoon vanilla extract
 1 1/2 cup all-purpose flour
 2 teaspoons baking powder
 1 1/2 teaspoon salt
 2 cupa brown sugar
 1 bag semi-sweet chocolate chips

 DIRECTIONS Place butterscotch chips and butter into a glass bowl or measuring cup. Heat in the microwave, stirring at 30 second intervals until smooth. Set aside to cool. Preheat the oven to 350 degrees F Grease a 9x 13 inch pan. In a large bowl, beat the butterscotch chip mixture with eggs and vanilla until well blended. Combine the flour, baking powder, and salt; stir into the batter until evenly mixed. Mix in the brown sugar, and chocolate chips. Spread the batter evenly in the prepared pan. Bake for about 35 minutes in the preheated oven, just until the bars aren't jiggly in the center and a pick comes out mostly clean.  Don't overbake.   Cut into squares while warm.