In a large bowl, beat cream cheese and peanut butter until smooth.Beat in powdered sugar and then 3 cups of Cool Whip.
Spread just a little peanut butter mixture in the bottom of a 9-inch square pan. This will help hold the graham crackers in place when you spread the peanut butter mixture on top of them.
Arrange graham crackers to cover the bottom of the pan, breaking the graham crackers as needed.
Spread half the peanut butter mixture on top of the graham crackers.
Repeat with another layer of graham crackers and the remaining peanut butter mixture.
Top with a final layer of graham crackers.Spread remaining Cool Whip on top.
Sprinkle the peanut butter cups on top and drizzle with fudge sauce.Refrigerate at least 2 hours before serving.