Preheat the oven to 400 degrees.

Place your unbaked pie crust into a nine-inch pie tin, crimp the edges and then prick the bottom all over with a fork.

Place a sheet of parchment paper into the crust to line it and fill it with pie weights or dry beans.

Bake for 15 minutes, and then carefully remove the parchment paper and weights, and bake for another 15 minutes or until the crust is golden.

Set it aside to cool.

In a saucepan, add the peanut butter chips, sweetened condensed milk, butter and salt and heat over medium heat. Stir regularly until everything is melted together.

Add in the marshmallows, and continue stirring until they melt into the mixture.

Pour the mixture into the prepared crust.

Evenly sprinkle all of the peanuts on top of the filling, and set the pie aside.

For the final layer, add just the sugar to a small pot and heat it over medium, stirring constantly. The sugar will melt and turn amber. At that point, add the butter, and stir until it is melted.

Carefully pour in the heavy cream, and let the mixture cook, still stirring constantly, for another minute on the heat.

Remove the pot from the stove and stir in the vanilla and 1/2 teaspoon salt. Let the mixture cool for at least five minutes before pouring evenly over top of the peanuts.

Refrigerate for about four hours or until the pie is cooled through. Before serving, sprinkle the top with coarse or flaked salt, to taste.

Store leftovers in an airtight container.