Unfold the pastry sheet on a lightly floured surface. Roll the pastry sheet into a 16 x 12-inch rectangle. With the short side facing you, spoon the apple mixture ... until the strudel is golden ...
Spread the cooled apple purée over the layer of marzipan, then brush the pastry border with a little of the beaten egg. Fold the second sheet of puff pastry in half lengthways, then carefully ...