Beat together the Quark, milk, vanilla extract and sugar until smooth.
Using a food processor reduce the pumpernickel to fine crumbs. Finely grate the chocolate and mix with the pumpernickel crumbs.
Drain the cherries well. Now make layers in a large glass dish or 6 wine glasses. Put cherries at the base and spoon on some Quark. Scatter over the Pumpernickel.
Repeat the layers saving a few cherries and crumbs for the top. Finish with a Quark layer, then put the last few cherries on top and sprinkle lightly with crumbs for an attractive finish. Chill overnight and serve.