Preheat your oven to 350 degrees. Crush the graham crackers into fine crumbs using a food processor, or by rolling them with a rolling pin in a plastic bag. In a medium bowl, stir together the crumbs, dark brown sugar, salt, and melted butter until well combined.
Press the crust firmly into your pie plate all the way up the edges. Bake the crust for 8-10 minutes, or until lightly golden and set. Let the crust cool completely.
For the filling:
In a large bowl, beat the cream cheese until very smooth. Add in the smooth peanut butter, 1/4 cup powdered sugar, vanilla extract, and salt and beat until well combined.
In another large bowl, beat the heavy cream until stiff peaks have formed. Reserve about 1/3 of the whipped cream in a small bowl, and add the powdered sugar to this mixture.
Fold the remaining 2/3 whipped cream into the peanut butter mixture until well combined and fluffy. Spread this mixture into your cooled crust evenly.
Top the pie with the remaining whipped cream in any design you prefer. Optionally, melt the milk chocolate and drizzle over the top of the pie before covering and chilling for at least two hours before slicing and serving. Enjoy!