1. Mix Cool Whip and creamy peanut butter together until incorporated, set aside.
2. Line an 8 1/2 x 4 1/2" loaf pan with parchment paper, allowing extra to hang over the sides of the pan.
3. Unwrap 3 of the ice cream sandwiches and cut one in 1/2. Leave the other 2 whole. Arrange ice cream sandwiches in bottom of pan - working to create a base.
4. Top the ice cream sandwiches with 1/3 of the peanut butter spread. Sprinkle with half the chopped peanut butter cups.
5. Repeat ice cream sandwich steps above. Top with 1/3 of the peanut butter spread. Sprinkle with remaining peanut butter cups.
6. Cover with plastic wrap and place in the freezer for at least an hour until firm. Place remaining 1/3 peanut butter spread in fridge or freezer depending on when you're serving.
8. Remove from freezer and lift parchment to remove the cake from the pan. Using a knife, spread remaining peanut butter topping over sides and enjoy!