Place the Läckerli and jam in a small bowl, pour over boiling water, cover and stand for approx. 5 mins., stir until smooth.
Tip the egg yolks and sugar into a thin-sided bowl. Using the whisk attachment on a hand mixer, beat in the hot bain-marie (just below boiling point) until the mixture has turned paler and creamy. Remove the bowl from the bain-marie. Stir in the Läckerli mixture in batches, continue stirring until the mixture has cooled. Stir in the lemon juice. Beat the cream until stiff, carefully fold into the mixture with a rubber spatula. Divide the Läckerli mixture into the glasses, cover and freeze for at least 3 hours.
Heat the berry mixture with the sugar over a medium heat then add the lemon juice.
Decorate the dessert plates with a little icing sugar or cinnamon. Combine the crème fraîche and icing sugar. Distribute the warm berry mixture over the parfait, decorate with a little crème fraîche and a few strips of Läckerli. Serve the Läckerli parfait on the dessert plates.