For the puff pastry pralines, first prepare the puff pastry.
Quickly knead the flour, salt and water into a firm dough and let it rest in the refrigerator for a quarter of an hour. Cut the dough crosswise and roll it out. Place the butter dough in the center of the dough and fold the dough over it and roll it out again (it is best to use a wooden walker). Fold the dough over again and let it rest for a quarter of an hour. Repeat the procedure 2 more times.
Place jam mounds on half of the rolled out dough with a small spoon, brush all around with egg and place the second half of the dough on top.
Cut out or cut with a pastry wheel. Brush the puff pastry pralines with the remaining egg and bake in a preheated oven at 200°C for about 15 minutes.
If desired, serve the puff pastry pralines sprinkled with powdered sugar.