Wash the cherries and remove their pits. Sprinkle them with the sugar and 2-3 tablespoons of breadcrumbs and mix. Lay out the puff pastry and at one end sprinkle some breadcrumbs and pour on some of the cherry mixture.
Wrap the puff pastry with the cherries, tucking one end under the other and gently pressing. Brush the top with a beaten egg yolk. Make decorative incisions on the top and bake until golden in a preheated 356°F (180 °C) oven.
Sprinkle it with powdered sugar and serve slightly cooled.