In a stand mixer, whip the heavy whipping cream on high until soft peaks form (whipped cream). Set aside.
In a stand mixer on low, blend together the creamy peanut butter, softened cream cheese, brown sugar, and vanilla extract until combined. Then, by hand, fold in 1 cup whipped cream until just combined (do not overmix).
Spoon the filling into the pie crust, cover, and refrigerate or freeze.
When you're ready to serve, garnish the pie with chopped peanut butter cups and the remaining whipped cream.