1 loose-bottomed 10-inch fluted tart pan, 2 inches deep
Steps
Set aside 6-10 oreos for later use. Place the entire packet of oreos (about 30) and chocolate into a food processor and blend until they form a crumb mixture. Add the butter and process until the mixture starts to clump together.
Press the mixture into a fluted tart pan, making a smooth base and sides with your hands. Put it into the refrigerator to chill and harden.
Melt the marshmallows in a saucepan over low gentle heat along with the milk. Once the milk starts to bubble (not boil), take off the heat and keep stirring until the marshmallows blend into the milk to make a smooth mixture.
Pour the mixture out of the saucepan into a heatproof bowl, then mix in the creme de menthe and creme de cacao. Leave until cool.
In a medium bowl, whisk the cream until it starts to hold soft peaks then, still whisking, add the cooled marshmallow mixture. This filling should be thick but still soft.
Spread the filling evenly into the chilled base and chill overnight or for a minimum of 4 hours until firm.
Crush the remaining cookie and sprinkle it over the top of the pie before serving.
