1. Beat cream cheese until slightly smooth.
2. Slowly add powdered sugar until it is all incorporated. Beat in peanut butter and mix until well blended.
3. With spatula fold in 8 ounces of Cool whip until mixture is smooth and creamy and totally blended.
4. Pour into graham cracker crust and chill for at least 2 hours.
5. Before serving top with up to 2 cups of additional cool whip depending on how thick you like the topping. Take the frozen candy bars and shave them over the top of pie for garnish. I prefer to use a plain chocolate bar, or you can chop up a Reese's peanut butter cup and sprinkle on top for a garnish.