1 envelope unflavored gelatin
1 cup granulated sugar, divided
1/8 teaspoon salt
3 eggs, separated
1/4 cup brewed and cooled coffee with chicory
1 teaspoon coffee liqueur or vanilla extract
3/8 cup heavy cream, whipped
1 (9-inch) graham cracker pie crust
Mix together gelatin, 1/2 cup sugar and salt in top of double boiler. Beat together egg yolks and coffee. Stir into gelatin mixture. Cook over boiling water, stirring constantly, until dissolved. Remove from heat and stir in coffee liqueur or vanilla extract. Chill until it is the consistency of unbeaten egg whites.
Beat egg whites until soft peaks form. Gradually add 1/2 cup sugar, beating until stiff and dry. Fold in gelatin mixture and whipped cream. Turn into pie crust and chill until firm.