For the dough: Mix together the flour and salt in a bowl. Beat the oil and egg together and mix into the flour. Slowly add the water while stirring until a ball of dough forms. Dust a clean work surface with some flour. Knead the dough intensely until it is smooth and silky. Lay a large smooth kitchen towel on a clean work surface and generously flour the towel. Place the dough in middle of the towel and roll out into a large thin rectangle. Brush the dough with some butter and sprinkle with the breadcrumbs to cover the entire dough surface.
For the apples: Put the apples into a large bowl. Sprinkle with the sugar and cinnamon and gently toss to mix well.
Preheat the oven to 350 degrees F.
Brush a baking sheet with butter and set aside. Place the long side of the dough closest to you. Mound the apples into a log along the bottom edge of the rectangle, leaving about a 2-inch border from the sides and the edge of the dough closest to you. Roll up the strudel jelly-roll style using the towel as an aid and beginning at the edge closest to you. Gently tuck in the sides and transfer the strudel seam-side down to the baking sheet. Brush generously with butter. Bake until lightly golden, 50 to 60 minutes.
Let the apple strudel cool for at least 15 minutes before slicing. Serve with vanilla ice cream and whipped cream and a dusting of sugar. And there you have an authentic German dessert.