Mix gluten free graham cracker crumbs, melted butter, and sugar together, then press firmly into the bottom of a 9-inch pie pan and refrigerate.
Beat cream cheese, peanut butter, powdered sugar, and vanilla extract together until smooth and creamy.
In a separate bowl, whip the heavy cream until stiff peaks form.
Gently fold the whipped cream into the peanut butter mixture until fully combined.
Fold in chopped peanut butter cups, reserving some for topping.
Pour the filling into the prepared crust, smooth the top, and sprinkle with remaining peanut butter cup pieces.
Freeze for at least 4 hours or refrigerate overnight until firm, then slice and serve.