Gather all ingredients.

Crush cookies and set aside 1/4 cup of crumbs. Place remaining crumbs in a medium bowl and mix in melted butter; press mixture firmly into the bottom and sides of a 9-inch springform pan.

Mix marshmallow fluff and crème de menthe together in a large mixing bowl until smooth.

Beat cream in a chilled glass or metal bowl with an electric mixer until soft peaks form; fold into marshmallow mixture.

Pour mixture into prepared crust and sprinkle reserved cookie crumbs on top. Freeze until firm, at least 2 hours. Remove from freezer 20 minutes before serving to soften slightly.