Preheat the oven to 350°F (175°C).
Combine graham cracker crumbs and melted butter in a bowl.
Press the mixture into the bottom and sides of a pie dish.
Bake the crust for 8–10 minutes until lightly golden.
Allow the crust to cool completely.
Beat together the cream cheese and peanut butter until smooth.
Add powdered sugar and vanilla extract, and mix well.
Whip the heavy cream until soft peaks form.
Gently fold the whipped cream into the peanut butter mixture.
Pour the peanut butter filling into the cooled crust.
Chill the pie in the refrigerator for at least 4 hours, or overnight.
Top with chopped peanuts if using, and serve.