Set about 5 aside if you’d like to top yours with crumbled Oreos.
Pulse the Oreos finely in a food processor until they form fine crumbs. (You can also crush them by hand.)
In a large bowl, mix together the melted butter and the Oreo crumbs.
Spread the Oreo mixture onto the bottom of a 9 x 13-inch pan and press down to form a firm crust.
Beat the cream cheese with an electric mixer in a large bowl until smooth.
Add half of the Cool Whip along with the peanut butter and powdered sugar. Beat on medium-high until smooth. Spread it over the Oreo crust.
Combine the cold milk and instant pudding and prepare it according to package instructions. Spread it over the pie once set. Top with remaining Cool Whip.
Decorate the top with crumbled Oreos or chocolate shavings.
Best if chilled for a couple of hours prior to serving.