Pulse oreos in a food processor until very fine. Add melted butter and pulse again until butter is evenly distributed. Press mixture into a lightly greased 9" pie plate being sure to push the mixture up the sides. Set aside.
For the filling, beat cream cheese and peanut butter together until smooth with no lumps. Add powdered sugar and vanilla and beat again until smooth.
In a separate bowl, beat heavy cream until stiff peaks form. Fold into peanut butter mixture until fully combined.
Pour into crust and refrigerate for 4-6 hours or preferably overnight. You can also freeze the pie and serve if you'd like a firmer pie.
Just before serving, prepare dark chocolate whipped cream. Beat heavy cream to stiff peaks. Add cocoa powder, powdered sugar and vanilla until combined. Pipe or spread onto pie.
Garnish with melted peanut butter, chocolate syrup and candy pieces, if desired, before serving.