For crust: Combine the Oreo crumbs and the melted butter in a mixing bowl, stir till well blended. Press onto the bottom and up the sides of a 9" pie plate.
Bake at 375° for 8-10 minutes. Cool completely.
For filling: Break Symphony bars into pieces and place in a large glass bowl with the milk. Melt at 50% power in the microwave. Cool slightly.
Whip the cream till stiff peaks form. Beat in the vanilla. Stir into the cooled chocolate mixture. Spoon into the crust.
Cover pie and freeze for at least 3 hours. Let sit at room temperature for 10 minutes before serving. Garnish with additional whipped cream and broken Symphony bars if desired.