Skin-on apple and walnut strudel

Volumes are approximate. For baking, use a scale; Metric keeps the specified gram weights.

• about 2 cups (250 g) bread flour, including 15 g reserved for rolling
• about ½ cup + 1 tbsp (135 g) warm water, for the dough
• 20 g neutral oil, divided
• 5 g distilled vinegar
• 2 g salt
• about 1 lb + 9 oz (700 g) raw apples with skin, cored and thinly sliced
• about 2 ½ oz (70 g) raw walnuts, finely chopped
• about 1 ¾ oz (50 g) plain dry breadcrumbs, verified vegetarian
• about 3 ½ tbsp (50 g) unsalted butter, divided
• about ¼ cup + 2 ½ tbsp (80 g) granulated sugar
• about ⅔ tsp (2 g) ground cinnamon
• about 1 ⅓ tbsp (20 g) lemon juice

Let’s make it

1. Combine about 2 cups (235 g) bread flour, warm water, 15 g oil, vinegar and salt. Knead for 10–12 minutes until smooth and elastic. Coat with the remaining 5 g oil, cover and rest for 60 minutes at room temperature. Reserve the remaining 15 g flour for rolling.
2. Meanwhile, cook apples, sugar, lemon juice, cinnamon and about 1 ⅜ tbsp (20 g) butter in a wide skillet for 12–18 minutes until slices soften and released liquid reduces to a coating; do not drain. Spread all filling in a shallow dish and cool for at least 30 minutes. Toast breadcrumbs in about 2 tsp (10 g) butter for 3–4 minutes and cool separately. Stir walnuts into the cooled apples.
3. Heat oven to 375°F (190°C). On a clean smooth cloth dusted with the reserved flour, roll dough into a rectangle, then gently stretch over the backs of your hands to about 24 by 20 inches (60 by 50 cm), thin enough to see the cloth faintly. Stretch thicker edges gently rather than trimming. Melt the remaining about 1 ⅜ tbsp (20 g) butter; drizzle half over dough and distribute crumbs. Place filling in a band along one short edge, leaving a border. Fold sides inward, then use the cloth to roll into a roughly 20-inch (50 cm) log.
4. Transfer seam-side down to a parchment-lined baking sheet, bending into a shallow horseshoe if needed. Brush with remaining butter. Bake for 40–50 minutes until golden and the dough layers are cooked through. Cool on the sheet for 30 minutes before cutting into 10 slices. Refrigerate leftovers within 2 hours, use within 3–4 days and reheat to 165°F (74°C).