Pour heavy cream into a medium mixing bowl (or 4 cup liquid measuring cup) and using an electric hand mixer whip heavy cream until very stiff peaks form.
In a separate large mixing bowl, using the same beaters and mixer (no need to clean) set on low speed, mix peanut butter, cream cheese, powdered sugar and vanilla if using until combined.
Increase speed to high and whip until fluffy, about 1 minute.
Add whipped cream to peanut butter mixture and fold until evenly combined**.
Pour mixture into pie crust and spread into an even layer.
Freeze 1 hour or refrigerate for 4 hours.
Decorate if desired (with topping ideas listed below) and slice.
Notes
*A store-bought graham cracker crust will work too. Or you can use a recipe for a homemade Oreo or graham cracker crust. Recipes are listed up above in blog post.
**It will take a bit of folding to fully incorporate, it won't seem to want to come together at first.
TOPPING IDEAS (OPTIONAL)
Sweetened whipped cream
Lightly heated peanut butter
Hot fudge sauce or chocolate ganache (cool slightly so it doesn't melt pie)