Preheat the oven to 350°F (175°C).
In a medium bowl, combine graham cracker crumbs and melted butter until evenly mixed.
Press the mixture evenly into the bottom and up the sides of a 9-inch pie dish.
Bake the crust for 10 minutes, then remove from oven and let cool.
In a large bowl, mix the sweetened condensed milk and peanut butter until smooth.
Add the powdered sugar to the mixture and mix until completely combined.
Stir in the chopped peanuts and 1 cup of caramel sauce into the filling mixture.
Pour the filling into the cooled pie crust, smoothing it out evenly.
Bake the pie for 25-30 minutes until the edges are set but the center is slightly jiggly.
Once baked, allow the pie to cool completely before drizzling with additional caramel and refrigerating for at least 2 hours.
Serve chilled topped with whipped cream if desired.