Kahlua Ice Cream Pie

1 (8 1/2 ounce) package chocolate wafers,
    finely crushed (about 40 wafers)
3 tablespoons granulated sugar
5 tablespoons butter, melted
8 ounces cream cheese, softened
1/4 cup dark rum
1 quart coffee ice cream, softened
1 cup heavy cream
2 tablespoons granulated sugar
1 to 2 tablespoons Kahl