Preheat oven to 350 degrees and spray a 9" pie dish with cooking spray. Crush the chocolate sandwich cookies into fine crumbs then stir together with melted butter until completely combined. Press the crust mixture into the pie dish using a flat-bottomed cup such as a measuring cup. Bake the crust 6 minutes then remove from the oven to cool.
Next, add the sugar, cornstarch and salt to a medium-sized saucepan (off the heat). Add the egg yolks and whisk until completely combined and a smooth paste forms. Slowly add the milk, whisking the mixture to completely dissolve the paste.
Place the saucepan over medium heat, whisking constantly until the liquid thickens and comes to a bubble. Continually remove the thickened pudding from the bottom of the pan and stir constantly or it will scorch.
Once the first bubble appears, reduce the heat to low and continue to cook for exactly 1 minute, whisking vigorously and constantly. Remove the pudding from the heat and whisk in the vanilla and peanut butter until completely smooth and well combined. Transfer the pudding to the pie crust and smooth into an even layer or slightly higher in the center. Cover with plastic wrap and place in the fridge for at least 4 hours or until completely chilled.
Just before serving, remove the pie from the fridge, cover with whipped topping and sprinkle with chopped peanuts. Enjoy!
One Last Thing
You need to stir constantly when cooking pudding from scratch. Since pudding thickens on the bottom of the pan first, it must be stirred vigilantly to avoid scorching. Be patient—it’s worth it!