In a double boiler, begin to melt both the cannabis milk and the marshmallows. Continue melting until it reaches a smooth consistency, stirring slightly. Remove one pot from the double boiler, set aside and allow to cool at room temperature, until the mixture has reached room temp. Now mix in the whipping cream until once again smooth. Pour this into the prepared pie crust and place in the refrigerator until chilled. Serve and enjoy. Leave any uneaten remains in the refrigerator.