Crush 4 pieces of fudge biscotti until it resembles graham cracker crumbs.
Mix peanut butter with the crushed fudge biscotti crumbs and spoon into the bottom of 4 baking cups.
In small mixing bowl combine the chocolate pudding packet and water until smooth and creamy. (You can also add sugar free Cool Whip to this mixture to make it more like a mousse and to give you more to put in your cup).
Spoon into the 4 baking cups on top of the biscotti mixture. Use Reddi Whip to garnish.