Prepare the Oreo Base: In a food processor, pulse the Oreo cookies (entire cookie, including the cream) until they turn into fine, sandy crumbs. Pour in the melted butter and pulse again until the crumbs are evenly coated.
Press & Set the Crust: Transfer the buttery crumbs into a 9-inch pie dish. Use the bottom of a flat measuring cup to press the mixture firmly into the bottom and up the sides. Place the dish in the freezer for 15 minutes to "lock" the crust in place.
Whip the Cream to Perfection: In a chilled large bowl, beat the cold heavy whipping cream until stiff peaks form (the cream should stand straight up when you lift the whisk). Warning: Stop immediately once peaks form to avoid turning it into butter!
Cream the Filling Base: In a separate mixing bowl, beat the room-temperature cream cheese and powdered sugar until the mixture is silky smooth and there are absolutely no lumps left.
Flavor & Color: Add the pure mint extract and green food coloring to the cream cheese mixture. Mix until the color is a uniform, vibrant "Shamrock Green."
The Gentle Fold: Using a rubber spatula, add the whipped cream to the green base. Gently fold (do not stir!) by cutting through the center and lifting from the bottom until combined. This keeps the pie light and airy.
The Chill Phase: Pour the filling into your set Oreo crust and smooth the top with an offset spatula. Cover loosely and refrigerate for at least 6 to 8 hours (overnight is best) to allow the fats to stabilize and make the pie sliceable.
The Perfect Serve: Right before serving, pipe swirls of whipped cream around the border. Sprinkle with mini chocolate chips or extra Oreo crumbs and place a maraschino cherry on each slice. Use a hot, dry knife for clean, bakery-style cuts!