Prepare your workspace by setting out the cream cheese to soften at room temperature for about 30 minutes before beginning. This ensures a smooth, lump-free filling.
Beat the cream cheese and peanut butter together in a large mixing bowl until completely smooth and well combined, about 2 minutes on medium speed. Scrape down the sides of the bowl halfway through.
Add the powdered sugar and vanilla to the peanut butter mixture, beating on low speed until incorporated, then increase to medium-high for another minute until the mixture becomes light and fluffy.
In a separate bowl, whip the heavy cream with the granulated sugar until stiff peaks form. Be careful not to overbeat, which can make the cream grainy or buttery.
Gently fold half of the whipped cream into the peanut butter mixture using a rubber spatula, maintaining as much air as possible in the mixture. Once incorporated, fold in the remaining whipped cream until no streaks remain.
Transfer the filling into the graham cracker crust, spreading it evenly with a spatula and creating decorative swirls on top if desired.
Refrigerate the pie for at least 3 hours or overnight to allow it to set properly. The texture improves with longer chilling time.
Just before serving, garnish the pie with crushed peanuts or peanut butter cup pieces, and if desired, drizzle with a little honey or maple syrup for extra shine and sweetness.