Chocolate Marble Mousse Pie

Directions

1. 1
   Mix gelatin, salt and 1/4 cup of the sugar in the top of a double boiler. Beat in the egg yolks, milk and rum. Cook over boiling water, stirring until slightly thickened. Take off the heat and blend in the chocolate chips until all are completely melted. Chill in refrigerator until thickened, but not set.
2. 2
   Beat egg whites til foamy; add the 1/2 cup sugar gradually and beat until the egg whites are very stiff.
3. 3
   Gently fold the egg white mixture into the chocolate mixture.
4. 4
   Whip the heavy cream with the remaining sugar and vanilla until stiff.
5. 5
   Alternate the two mixtures in the cold pie shell, dolloping each with a big spoon; then swirl them together to marble. Be careful not to overdo.
6. 6
   Chill the pie until firm.