Spray an 8x8-inch square baking dish with cooking spray.
For pudding: Combine the pudding mix, about 1/2 cup of the milk, and the peanut butter in a large mixing bowl. Beat with an electric mixer till smooth, then gradually beat in the remaining milk. Continue beating for about a minute, or until smooth and creamy. Set aside.
For sauce: Whisk the hot fudge and peanut butter in a small bowl until smooth.
*Whipped cream: Beat the cream at high speed until soft peaks form. Add the powdered sugar and vanilla and beat until stiff peaks form.
Assemble:
Arrange Nutter Butter cookies in an even layer in the bottom of the prepared pan. (I needed 12 1/2 cookies.) Spread 1/3 of the pudding, 1/3 of the sauce, 1/3 of the whipped cream, and 1/3 of the chopped peanut butter cups.
Repeat the layers 2 times, ending with the whipped cream. Cover with plastic wrap and chill for at least 3 hours, or overnight.
When ready to serve, top with the remaining 1/3 of chopped Reese's and peanut butter chocolate sauce. Cut into squares and serve cold.
Notes
A 16-oz box of Nutter Butters only has 32 cookies. I buy the snack pack box that comes with 10 packets of 4 cookies each.
*Cream will beat up faster and fluffier if you place your beaters and glass or metal bowl in the freezer for 10 minutes first.
You can use an 8 ounce tub of Cool Whip in place of the whipped cream layer. Just note that your dessert will be sweeter.
If you use crunchy peanut butter, you will need 1/3 cup in both the pudding and the sauce.
For easy, even drizzle on the top layer, you can place the sauce in a zip lock bag and snip the corner.
You can double this recipe and make it in a 9x13" pan. You will only need to do two layers, and may have leftover cookies.