For the dough, combine the flour, oil and salt in a bowl. Slowly add water, stirring in enough to form a dough that is soft but not sticky. You may need to add a little more water than the recipe calls for.
Once the dough comes together, knead for 8-10 minutes until smooth and elastic. Cover and rest for 30 minutes.
After resting, knead the dough again for another 8-10 minutes. This second kneading is necessary to make the dough very flexible. Now using a pastry cloth lined surface, flatten the dough out slightly. Cover and rest again for another 30 minutes.
After the second rest, begin stretching out the dough. Start from the middle and work your way out to the edges using a pulling motion. Walk around the table as you stretch so the pastry maintains an even surface. Try to maintain and square or oval shape that is symmetrical. The dough should be thin enough to read a newspaper through. If desired, trim the edge. (See notes for how you can use these scraps.)
Preheat oven to 375F/190C. Oil the bottom of a 9"x13" baking pan or even a baking sheet. Peel, core and slice the apples into uniform pieces. Drizzle 2 tablespoons of the oil over the dough. Sprinkle apples evenly over, followed by the sugar, raisins and cinnamon. Grab the tablecloth on either side of the horizontal way of the strudel and begin rolling it up. Continue using the tablecloth to roll it the entire way as the dough would tear by handling it.
Carefully place the strudel into the prepared pan and brush with remaining 1 tablespoon oil. Bake for 45 minutes or until lightly golden. Sprinkle with powdered sugar if desired. Enjoy!