Put the biscuits in a freezer bag and crumble them into crumbs with a cake roll. Mix butter and biscuit crumbs. Divide the biscuit mixture into 3 dessert rings (approx. 8 cm Ø), press them and chill
Grate the lemon peel thinly and squeeze the juice. Stir cream cheese, vanilla pulp, lemon peel and 2 tablespoons lemon juice until smooth. Sweeten with 20 g icing sugar. Separate the egg. Beat egg yolks, 2 tbsp. sugar and vanilla sugar until fluffy. Fold in cream cheese
Spread the cream on the cake bases and smooth it down. Put the tartlets in a cool place. Wash the blueberries and strawberries and drain well. Sort the raspberries. Finely puree the strawberries and raspberries with a hand blender, except for a little bit for garnishing. Sweeten with 1 tablespoon icing sugar
Whisk the egg white with the whisk of the hand mixer, adding 2 tablespoons of sugar. Spread the blueberries and beaten egg whites over the tartlets. Flame off with a gas burner. Arrange tartlets and sauce and decorate with remaining berries