For the puff pastry, heap flour on a work surface, make a well in the center and mix with all ingredients to form a smooth dough. Let rest for at least 30 minutes.
Roll out the dough and cut into even 8 x 8 cm squares.
Spread a little jam on each and fold the dough into a triangle. Press edges well, brush the pouches with beaten egg and let rest for about 10 minutes.
Place on a baking tray lined with baking paper and bake in a preheated oven at 180 °C for 15-20 minutes.
Remove, let cool slightly and sprinkle with powdered sugar.