Process 28 crushed Mint Oreo cookies until fine crumbs. Mix with 5 tablespoons of melted unsalted butter. Press into a 9-inch pie plate and freeze for 30 to 60 minutes.

In a microwave-safe bowl, soften 1 cup of marshmallow crème for 30 to 45 seconds. Whip 1 cup of heavy cream until stiff peaks form.

Combine softened marshmallow crème with 1/4 cup of crème de menthe until smooth.

Gently fold whipped cream into the marshmallow mixture until fully combined.

Pour mint filling onto the crust, smoothen, cover with plastic wrap, and freeze for at least 5 to 6 hours.

Let the pie sit at room temperature for 10 to 15 minutes before slicing. Serve chilled.