Line your pan with a layer of graham crackers.
In a bowl, mix vanilla pudding, milk and peanut butter until smooth. Fold in cool whip.
Pour 1/2 of the mixture on to the crackers.
Add another layer of graham crackers.
Top with the rest of the pudding mixture.
Add a final layer of graham crackers.
Melt chocolate frosting in microwave for 1 minute and pour over.
Place In the refrigerator for at least 12 hours.
Remove from refrigerator.
Cut into square.