In a medium saucepan, mix gelatin, 1/4 cup sugar, spices and salt. Add yolks, eggnog and pumpkin. Beat until mixture is evenly blended. Cook very slowly, stirring constantly, until gelatin dissolves and mixture thickens slightly. Pour into a large bowl. Chill about 20 minutes, until cold.

In a plastic bag, finely roll 1 package of graham crackers. Blend crackers, 1/4 cup sugar and melted margarine together with a fork. Press onto bottom of a flan pan. Chill 30 minutes. Beat egg whites until foamy. Slowly beat in 1/2 cup sugar until meringue forms firm peaks. Fold into pumpkin mixture. Spoon into flan pan. Chill overnight. Serve topped  with Cool Whip.