Spread peanut butter mixture over warm crust. Place chocolate chips in small resealable food-storage plastic bag; seal bag. Microwave on High 1 to 2 minutes or until melted. Cut very small hole in 1 corner of bag; squeeze bag to drizzle chocolate over peanut butter mixture. Sprinkle baking bits evenly over top. Let stand until chocolate is set, at least 30 minutes. For bars, cut into 6 rows by 4 rows.