Let the puff pastry thaw. Roast the pine nuts and hazelnuts. Remove the loose shells from the hazelnuts and grind the hazelnuts. Roast the breadcrumbs and mix with the ground hazelnuts. Squeeze the lemon and use it to make lemon water. Peel the apples, cut in half, cut into small pieces and place in the lemon water. Melt the butter. Mix the sugar with the vanilla sugar.
Brush a sheet of puff pastry with the butter, place a second on top, butter again and place a third on top. Roll out the puff pastry packet thinly. Sprinkle 2/3 of the rolled out dough with the hazelnut breadcrumb mixture. Spread the apple pieces and pine nuts on top. Then again hazelnut breadcrumbs mixture. Finally, sugar, cinnamon and calvados, fold in the short sides of the dough and roll up the dough. Press on the seam and brush the top with butter. Line a baking sheet with parchment paper and place the strudel on the parchment paper with the seam side down. Brush the strudel with butter all around. Sprinkle with the rest of the hazelnut breadcrumbs mixture. Repeat the process until all ingredients are used up.
Bake at 180 ° C top / bottom heat with convection for 40 - 45 minutes.
Arrange the strudel warm or cold with calvados vanilla sauce à la Didi and serve.
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