To make the dough, combine flour, water, oil, and salt in a bowl and knead all ingredients together to create a smooth, silky dough. Cover and let rest for about two hours.
Heat butter in pan, add dry breadcrumbs from white bread, sauté until golden brown, then chill. Peel and cut apples into slices and mix with sugar, cinnamon, and raisins.
Place a tea towel on table, dust with flour. Place the dough on the towel and sprinkle the dough with flour. Using a rolling pin, roll out the dough until the size of a pizza. Using the floured backs of both of your hands, carefully reach under the dough and stretch it to make a paper-thin rectangle. Then, cut off any protruding edges.
Sprinkle 2 spoons of buttered breadcrumbs over the dough, then 2 spoons of melted butter. Add the apple mixture to the shorter side of the rectangle, keeping it on 1/3 of the dough. Fold the sides of the dough over the apples first. Then fold the end up, closest to the apples. Now start rolling the dough by lifting the edge of the tea towel. Roll the strudel up tightly and close the ends.
Place strudel seam-side down on a buttered baking tray. Brush generously with melted butter. Bake in a preheated oven at 200 degree C for about 40 minutes.
Sprinkle a dusting of powdered sugar over the top.