Crumble the sponge finger and divide into 4 glasses. Sprinkle each with 2 tablespoons of coffee and press the biscuits onto the bottom. Sprinkle with liqueur and chill. Separate the eggs.
Beat the egg yolks and 25 g sugar until white and creamy. Add mascarpone and stir until smooth. Beat the egg whites until stiff, pour in 25 g sugar. Carefully fold the beaten egg whites into the mascarpone mixture and pour into the glasses.
Dust thickly with cocoa. Decorate with balm.