Step 1

Heat oven to 350°F. (325°F for dark or nonstick pan). Grease bottom of 9-inch square pan with shortening or cooking spray.

Step 2

Make brownie batter as directed on box. Stir in 1/4 cup each of the butterscotch, semisweet and white vanilla baking chips. Spread in pan.

Step 3

Bake 28 to 31 minutes or until toothpick inserted 2 inches from side of pan comes out almost clean. Cool 30 minutes.

Step 4

In small microwavable bowl, microwave remaining 2 tablespoons butterscotch chips uncovered on High 20 to 40 seconds, stirring halfway through, until chips can be stirred smooth. Spoon into resealable food-storage plastic bag; partially seal bag. Cut small tip from corner of bag; drizzle over top. Repeat melting and drizzling steps with remaining semisweet chocolate chips and white vanilla baking chips. Let stand about 2 hours or until toppings are set. Cut into 4 rows by 4 rows. Store covered in airtight container.