For the foam rolls, first roll out the puff pastry 2.5 mm thick and approx. 40 cm wide.
Brush the surface of the dough with beaten egg and cut into 2.5 cm wide strips with a pastry wheel. Overlapping 6-7 mm, roll up on the foam roll forms like a spiral.
Place end down on a baking sheet lined with parchment paper and press lightly against the baking sheet so that the rolls remain firm. Bake at 200 degrees in a heated oven for about 20 minutes. The puff pastry should be baked until light brown through and through.
For the meringue, mix egg whites and sugar and heat in a bain-marie to about 40 degrees. Whip to a foamy consistency.
Fill as fresh rolls as possible with the mousse and sprinkle very lightly with vanilla powdered sugar just to make it look nice.