How to make
From the puff pastry, cut out rectangles measuring 10/6 cm. The filling is placed along the long side and the pastry is closed. The edges are clipped. Making the surface notched with a sharp knife.
Bake at 430°F (220 °C). Cool and sprinkle with vanilla sugar. Prepare the filling: thaw and drain the blueberries. Add the sugar and heat until thickening. Cool.