For Oreo Pie Crust: Combine Oreo Base Cake and melted butter until well blended.
Firmly press mixture evenly onto bottom and up sides of an 8.75 inch (inside diameter) pie plate. Set aside until ready to use.
For Peanut Butter Mousse: Place cream cheese, peanut butter and powdered sugar in 12-quart bowl of electric mixer fitted with paddle attachment. Beat on medium speed until smooth, scraping side of bowl as needed. Slowly add milk and vanilla, scraping bowl between additions. Fold in whipped cream.
Spoon Peanut Butter Mousse evenly onto OREO Pie Crust. Refrigerate several hours or overnight. Pie must be firm in order to slice.
For Garnish: Whip cream and sugar until stiff peaks form. Place whipped cream in a pastry bag fitted with a large star tip. Pipe in a spiral around top edge of pie. Place OREO Small Cookie Pieces around outside edge of whipped cream. Sprinkle chopped peanuts over center of pie. Refrigerate until ready to use.