Heat oven to 350°. Coat an 8 x 8-inch baking pan with nonstick cooking spray.
In a medium bowl, whisk together flour, cocoa, salt and baking powder. Set aside. In a large bowl, combine sugar, oil, eggs and extracts. Stir in flour mixture until just moistened. Fold in walnuts and butterscotch chips. Spoon into prepared baking pan.
Bake at 350° for 22 minutes or until a toothpick inserted in center comes out clean. Cool completely.
Place chocolate chips and 1 tsp of the oil in a small bowl. Microwave on high 1 minute. Stir until melted. Place in a small ziptop bag and make a tiny snip in one corner. Pipe over cooled brownies. Repeat with butterscotch chips and remaining 1 tsp oil. Cut into 16 brownies.
For easy transport and storage, use Chinet paper baking pans. For more information, see page 150.)