Heat the oven to 220 °C and insert a roasting rack in the upper half. Put the apples in a saucepan with the sugar (1) and the water. Steam until soft, then pour in the blackberries and steam for another three minutes until soft. Put the fruit in an ovenproof dish with a capacity of about 1.2 liters. For the dough, put the flour with the baking powder and the salt in a suitable bowl and work in the light butter until you have a fine crumbly mixture. Stir in the sugar (2) and enough milk to make the dough smooth. (It should not be too wet.) Place the dough on a lightly floured board and roll out to a thickness of 1 cm. Cut out circles with a 4 cm wide scalloped cookie cutter. Place these dough circles overlapping and the edge of the pan on the fruit and brush with a tiny bit of milk. Bake in the oven for 10-15 minutes until the dough turns golden brown.
Variation: The recipe can also be prepared with preserved fruits such as raspberries, gooseberries, plums and apples or possibly apricots.