DO CRUST. In a bowl, combine first 3 ingredients and press evenly onto the bottom of an 8-inch pie pan. Chill.
DO FILLING. Beat cream cheese and powdered sugar until light and fluffy. Add vanilla and beat. In another bowl, whip all-purpose cream until stiff and doubled in volume. Fold into the cream cheese mixture. Take 1/3 of the cream mixture and set aside.
MELT chocolate pieces and milk in a saucepan. Stir into 1/3 cup whipped cream mixture.
LAYER. Pour remaining 2/3 cup of cream mixture into prepared crust. Spoon and dot chocolate cream into the cream mixture. Chill and serve.