Cut mango strips into small pieces. Put raisins, the mango pieces and cranberries in a bowl, pour rum over them, stir, cover and let sit for about 8 hours or overnight.
Thoroughly mix sugar, orange and lemon zest.
Add soft butter, vanilla as well as salt and beat it for about 5 minutes until it becomes a fluffy creamy light mixture.
Add eggs and beat until homogeneous.
Add quark and beat until homogeneous.
Add ground almonds and mix again until homogeneous.
Mix flour with baking powder, add it in portions to the quark mass and knead it briefly to a soft dough.
Knead the dried fruits with rum into the dough.
On a floured work surface, divide the dough into two equal pieces and shape each piece into a stollen by first flattening it into an oval and then folding one side onto the other.
Place the two quark stollen on a baking tray lined with baking paper and bake them in a preheated oven at 180 °C top and bottom heat for about 50 minutes. Cover them with a sheet of baking paper after about 25 minutes so that they do not burn on the surface.
Brush the still hot quark stollen with melted butter on all sides and sprinkle with powdered sugar.
Let the quark stollen cool to warm, wrap them in an airtight container and let them rest for at least 24 hours.
Dust the quark stollen again with powdered sugar before serving.