Heat oven to 350°F (325°F for dark or nonstick pan). In large bowl, beat cake mix, butter and eggs with electric mixer on medium speed until smooth. Stir in chopped granola bars. Onto ungreased cookie sheet, drop mixture by tablespoonfuls.
Bake 10 to 12 minutes or until set and light golden brown around edges. Let cool on cookie sheet 2 minutes. Remove from cookie sheet to cooling rack. Cool completely, about 30 minutes.
In small microwavable bowl, microwave peanut butter chips and shortening uncovered on High 15 seconds; stir. Microwave 15 to 25 seconds longer or until mixture can be stirred smooth. Spoon into small food-storage plastic bag. Cut off tiny corner of bag; squeeze bag to drizzle mixture over cookies. Let stand about 30 minutes or until drizzle is set. Store in airtight container.