Combine gelatin, sugar and salt. Stir in milk, egg yolks, bring to boil. Remove from heat, stir in peanut butter until smooth. Chill until partially set. Beat egg whites with 1/4 cup sugar to stiff peaks. Spoon fold into peanut butter mix. Fold in Cool Whip. Spoon into crust. Chill 2 to 3 hours. Drizzle with chocolate syrup before serving.