For the sour cherry cake, beat egg whites with sugar and water until foamy. Fold in milk, flour, oil and baking powder. Then pour into a cake baking pan lined with baking paper, approx. 35×25 cm or a cake pan.
Finally, spread the sour cherries on top – they sink into the dough and bake on the 2nd rack at 180 degrees for about 25-30 minutes.