In a mixing bowl, combine the crushed Oreo cookies with the melted unsalted butter. Stir until the crumbs are evenly coated. Press this mixture firmly into the bottom and sides of a 9-inch pie dish to form the crust. Make sure it's packed tightly for stability.
In another bowl, beat the cream cheese with an electric mixer until smooth and creamy. Gradually add in the powdered sugar, and continue to mix until fully incorporated.
Add the peppermint extract and green food coloring to the cream cheese mixture. Mix until the color is evenly distributed and the filling is smooth.
Gently fold in the Cool Whip until fully combined. This will give the filling its light and airy texture. Be careful not to deflate the mixture.
Stir in the finely chopped Andes Chocolate Mints, ensuring they are evenly distributed throughout the filling.
Pour the mint filling into the prepared Oreo crust. Spread it evenly with a spatula.
Cover the pie with plastic wrap and refrigerate for at least 4 hours, or until set. For best results, chill overnight.
Once set, slice the pie and serve it chilled. You can garnish with additional whipped topping or mint leaves for an extra touch!