Let raspberries thaw at room temperature. Crumble the rusks. Whip the curd with the whisk of the hand mixer. Stir in yoghurt, milk, lemon juice and honey. Flavour with sweetener.
Put some raspberries aside for decoration. Fold the remaining raspberries into the quark cream. Layer quark cream, crumbled onions and again quark cream in four dessert glasses. Serve decorated with raspberries and lemon balm