Wash and sort the blueberries and drain well. Mix with jam. Finely chop the chocolate. Crumble meringue coarsely.
Stir mascarpone, quark, sugar and vanilla sugar until smooth. Whip cream until stiff and fold in. First fold in meringue and chocolate, then briefly fold in the fruit mixture. Pour everything into a large bowl and chill until serving
Tip: The dessert should be prepared at short notice (max. 2-3 hours before), with longer standing time the meringue can dissolve