Chocolate Ice Box Cake

4 1/2 squares chocolate
3/4 cup sugar
6 tablespoons hot water
Pinch of salt
1 1/2 tablespoons cold water
1 1/2 teaspoons unflavored gelatin
6 egg yolks
1 teaspoon vanilla
6 egg whites
3/4 cup whipping cream
16 ladyfingers-split

Melt chocolate in top of double boiler; then add sugar, salt, and hot water, stirring until sugar is dissolved. Dissolve gelatin in cold water and add to hot chocolate mixture. Cook in double boiler until smooth and thick. Remove from heat. Add egg yolks, one at a time, beating mixture after adding each egg. Return to boiling water and cook 2 minutes, stirring constantly. Add vanilla and let cool. Fold in beaten egg whites and whipped cream. Chill. Line bottom and sides of angel cake pan with waxed paper and arrange split ladyfingers on bottom and sides of pan. Add alternate layers of chocolate mixture and ladyfingers. Chill 12 to 24 hours.