Knead the flour, powdered sugar, butter and poppy seed baking with your hands, wrap in foil and put in the refrigerator for 30 minutes. Beat the egg whites lightly until frothy. Shape the dough into 2 rolls and brush them with the egg white. Then roll vigorously in sugar.
Chill the dough for another 45 minutes. Then cut the rolls into pieces approx. 1 cm thick and place on a baking sheet (baking paper).
In the oven for about 15 minutes at 175 ° C. Let cool well on a wire rack.