Soften 1 envelope unflavored gelatin in 2 tablespoons cold water. Melt 3 (1 ounce) squares unsweetened chocolate in 1/2 cup water over low heat. Add softened gelatin, stir to dissolve. Beat 4 egg yolks until thick lemon colored. Gradually beat in 1/2 cup sugar. Add 1 teaspoon vanilla and a dash of salt. Gradually stir in chocolate mixture. Cool, then stir until smooth. Beat 4 egg whites and 1/2 teaspoon cream of tartar to soft peaks. Gradually add 1/4 cup sugar, beating to stiff peaks. Fold in chocolate mixture. Fold in 1 cup heavy cream, whipped. Stir in 1/2 cup chopped walnuts.

Line bottom of 8" spring form pan with lady fingers, cutting to fit. Line sides by standing up lady fingers on end all around. Fill with half the chocolate mixture, then make layer with additional lady fingers. Top with chocolate mixture. Chill 8 hours or overnight. 3 dozen lady fingers in all.