For the black cherries in curd leaf dough, mix flour and baking powder well and put in the mixing bowl of the food processor. Add curd, butter and salt and knead with the dough hook until smooth.
Chill the dough for at least 3 hours. Then roll out the dough into a rectangle, fold once from the right and once from the left, roll out again carefully and repeat three times. In between, chill the dough again and again.
Roll out the dough again and cut out circles with a round cookie cutter. Put a blob of black cherry jam in the center of the first half of each circle, then add a second circle on top.
Brush the edges with a little beaten egg white and press well together. Continue in this way until the dough is used up. Brush the circles with a little beaten egg yolk and bake in a 210 °C oven for about 15-20 minutes until golden brown.
Finally, sprinkle with a little powdered sugar.
You can keep this dough for 2 days and process it later, or you can process it immediately after 2 hours.