Break candy bar in medium sized pieces, leaving one small square aside. Under low heat, melt chocolate bar in small saucepan, gradually spooning in 1 tub of Cool Whip until candy bar is completely melted. It is important to continuously stir the chocolate so that it doesn't stick to the sauce pan.
Pour Cool Whip/candy into pie shell. Take the second tub of Cool Whip and cover the chocolate completely.
Take the left over square of chocolate and shave and curl. Place shavings over the Cool Whip. Cover the pie loosely with plastic from the pie shell, and place in the refrigerator. Let pie chill for at least 2 hours.