Stir water, oil, lemon juice and salt in one bowl.
Use your hands or wooden spoon to incorporate.Stir in one-half cup flour until well combined about 1 minute. Add remaining flour. If dough is sticky, add about 1 tablespoon more flour.
Knead dough until smooth, about 10 minutes. Slam it on the counter 2-3 times. Shape into smooth ball.
Add 1/2 tsp oil to clean bowl. Place dough in bowl, turn a couple of times to coat then cover with plastic wrap. Let sit at room temperature for an hour. Or you refrigerate up to 2 days.
Roll out dough on floured surface to about 12x15 inches. Pick up the dough and stretch it by letting it hang down and working it with your hands until it is very thin and approximately 20 x 15 inches. It should be fairly transparent. Place dough back on a floured surface.
Brush melted butter over half the dough across long side.
Spread breadcrumb mixture over other half of dough leaving a 1½ inch border around edges.
Top dough with breadcrumbs then apples, then drained raisins and then with walnuts. Finally, sprinkle cinnamon and sugar mixture over top.
Fold 1 inch side borders over filling. Then tightly roll strudel with the filling and continue to roll jelly roll style. Place seam side down on a parchment paper lined baking sheet. Brush with melted butter.
Bake on middle oven rack at 375° for 30-40 minutes until golden brown.
Remove from oven. Let cool slightly. Dust with powdered sugar. For crispiest taste, eat while hot.