Preheat the oven to 350. Line baking sheet with parchment paper. In a small bowl, soak raisins in hot water for 10 mins. Drain and add to a large mixing bowl along with the apples, cinnamon, lemon juice, sugar, flour, salt, raisins, and breadcrumbs.
On a linen towel, place down one sheet of filo and brush with melted butter. Lay another sheet on top, then brush with more butter. Repeat until you’ve used all filo sheets. Make sure to cover the unused filo dough with a towel while you are working to keep it from drying out.
Turn filo dough so the short side is facing you. Pile half of the apple filling on the third of dough closest to you, leaving a 2” border on one side. Fold the short edges over the Filling. Roll up jelly-roll style, starting with the side with the 2-inch border.
Repeat steps two and three with the second roll of filo dough.
Transfer to the prepared baking sheet and brush with melted butter.
Bake until golden brown, about 35 minutes. Let cool to room temperature, then sprinkle with powdered sugar and cinnamon before serving.
Vanilla Sauce
Beat the egg yolks and sugar together until the yolks are thick and pale yellow and the sugar is dissolved about 4 minutes.
Bring the milk to a boil in a saucepan. Transfer to the bowl with the egg yolks and sugar by slowly pouring in a thin stream, while whisking or using an electric mixer at the same time.
Pour mixture back into pan and heat over low heat, whisking constantly for 2-3 minutes or until it coats the back of a spoon. Remove from heat and stir in vanilla extract or vanilla bean. Pour through a fine sieve. Serve with the apple strudel.
Notes
If the vanilla sauce curdles, you can blend it in a blender for a smooth sauce.
If you want a richer sauce, you can use cream instead of milk.