To prepare crust, place wafers in a food processor; process until finely ground. Add 3 ounces melted chocolate and oil; process until blended. Press into bottom and up sides of a 9-inch pie plate. Freeze 15 minutes or until set.
To prepare the filling, combine sugar, cornstarch, cocoa, and salt in a large saucepan; stir with a whisk. Add half of milk and 2 yolks; stir with a whisk until smooth. Stir in the remaining milk. Cook over medium heat for 5 minutes or until thick and bubbly, stirring constantly. Remove from heat. Add 4 ounces chocolate, and stir until smooth. Stir in rum. Pour filling into prepared crust. Cover with plastic wrap; chill 4 hours or until set. Serve with raspberries and whipped topping.