Preparation

• 1
  Beat the egg yolk and sugar until it is pale yellow and smooth, this should take at least ten minutes. While beating combine the coffee and liqueur. Quickly dip the biscuits in this mixture and set aside to cool. Add the mascarpone to the egg yolk mixture and beat until combined. Beat the egg whites until stiff peaks are formed. Fold the egg white mixture into the yolk mixture.
• 2
  Alternatively layer the biscuits and the egg mixture ensuring that the final layer is the egg mixture. Top with dark chocolate shavings or cocoa and refrigerate for at least four hours before serving.