Mix the egg whites of 2 eggs into a snow and then let stand. Mix together the curd cheese, softened butter, sugar and just one yolk. Lift the snow under the curd mixture. Spread the puff pastry out on a baking sheet (leave the foil underneath) and draw a light line in the middle.
Spread the filling on the underside of the puff pastry. (Leave approx. 2.5 cm from the edge) Spread the drained pineapple on the filling. Whisk the rest of the yolk and spread it around the edge of the entire puff pastry with a brush and then fold the upper side exactly onto the lower side. Press the three open edges together with a fork and spread the remaining yolk over the whole strudel. Slide the strudel into the oven and bake until the surface is golden brown. Prepare the vanilla sauce according to the package description!