Separate 1 egg. Chill the egg white. Beat 1 egg, 3 egg yolks, sugar and lemon peel in a hot water bath with the whisk of the hand mixer for approx. 7 minutes until thick and creamy
Add the wine and lemon juice and continue beating until the volume has doubled. Then beat the cream in a cold water bath until cold
Beat 1 egg white and salt until stiff and carefully fold into the cream. Divide into 4 dessert bowls. Crumble the biscuits finely and sprinkle over them. Dust with icing sugar