How to make
Defrost the puff pastry and spread it out. Mix the marmalade or rosehip jam with the crushed walnuts.
I made them with homemade plum jam and they turned out great. Mix them well and spread the puff pastry with this mixture.
Then roll the puff pastry evenly from both ends and put the resulting double roll in the freezer for half an hour, in orde to harden well.
With a very sharp knife, cut the double roll into about 0.4″ (1 cm) thick slices.
Spread the resulting slices with beaten egg, arrange them in a baking pan and bake them in a preheated oven to 430°F (220 degrees).
Then sprinkle them with powdered sugar and ground walnuts if you like.