Line two 8 x 4 x 3 inch loaf pans with waxed paper.
Beat the egg whites until stiff. Beat the whipping cream until soft peaks form.
Melt chocolate in a double boiler. Blend in water. Remove from heat, and add egg yolks; beat vigorously until smooth. Add sugar, and mix well. Fold whipped cream into chocolate mixture. Fold in stiffly beaten egg whites.
Separate ladyfingers. Line bottom of each pan with single ladyfingers. Cut remaining ladyfingers in half crosswise, and use to line the sides of the pans. Fill with chocolate mixture. Chill 12 to 24 hours. Unmold. Serve with additional whipped cream if desired.