From the puff pastry, cut out squares with sides of about 4″ (10 cm). On every square, make cuts - about 3/4″ (2 cm), going from the outside corners toward the inside.
Put jam in the middle, it should not be runny. Bake in a preheated 428°F (220 °C) oven, for about 10 minutes.
After removing from the oven, sprinkle them with plenty of powdered sugar.