Combine flour and salt in a bowl.

Whisk together water, egg, and oil.

Pour wet into dry and mix until it forms a shaggy dough.

Turn dough onto a lightly floured surface. Knead 6–8 minutes until smooth and elastic.

Form a ball, oil lightly, and let rest covered for 30–45 minutes to relax the gluten.

Toss chopped apples with sugar, cinnamon, and raisins. Let sit 10 minutes to draw out some juices. Drain excess liquid if very wet.

Heat a skillet, melt 2 tablespoons butter, add breadcrumbs. Toast until golden and crisp. Remove from heat and let cool.

On a floured cloth or pastry mat, roll the dough into a rectangle about 12×16 inches. Use your hands to gently stretch until thin; you should see a faint translucence.

Brush the dough surface with a little melted butter. Sprinkle toasted breadcrumbs in a thin even layer, leaving a 1-inch border.

Spread apple mixture evenly over the breadcrumbs, keeping the mixture away from one long edge for sealing.

Use the cloth to help you roll the dough away from you into a tight log. Seal the seam and tuck the ends under.

Transfer to a parchment-lined baking sheet seam-side down. Brush with remaining melted butter.

Bake at 375°F (190°C) for 30–40 minutes, rotating once, until deep golden.

Cool 15–20 minutes before slicing. Cooling helps the filling set so slices hold.