In a bowl, combine crushed cookies and melted butter. Press into the bottom of a 9-inch springform pan. Refrigerate while preparing the filling.
Heat 1/2 cup cream in a small saucepan over medium heat until it just begins to simmer. Remove from heat and stir in chocolate chips until smooth. Let cool to room temperature.
In a large bowl, beat cream cheese and powdered sugar until smooth. Mix in crème de menthe and crème de cacao.
Stir in cooled chocolate mixture, then fold in the whipped cream until well combined.
Pour the filling over the crust and smooth the top. Refrigerate for at least 6 hours, or overnight.
Before serving, garnish with additional whipped cream, chocolate shavings, or crushed cookies if desired.