Melt chocolate in heavy saucepan over very low heat. Add instant coffee and stir until dissolved. Set aside to cool.
Soften gelatine in 1 tablespoon water in a small cup and set aside.
Combine sugar, salt, and water in a small saucepan and bring to a boil. Boil for 1 minute, and then cool to lukewarm.
Stir in melted chocolate, vanilla, and softened gelatine.
Beat egg yolks until very thick and lemon-colored, at least 5 minutes. Blend into chocolate mixture.
In a separate bowl, beat egg whites until stiff peaks form. Fold into the chocolate mixture.
Lay split ladyfingers or spongecake strips in bottom of well-oiled 9- by 5- by 3-inch loaf pan. Spoon in about 1 cup of chocolate mixture. Line sides of pan with split ladyfingers or spongecake strips, anchoring the ends in the filling. Fill the mold with alternate layers of chocolate filling and ladyfingers, ending with ladyfingers. Chill for at least 24 hours. Unmold on chilled plate. Serve at once.