Mix flour, water, egg, oil, salt and vinegar into a smooth dough. Lightly oil and let rest covered for 20–30 minutes at room temperature.
Roll out on a floured cloth and stretch very thin using the backs of your hands.
Peel and slice the apples, then marinate with lemon juice, rum and lemon zest. Sprinkle one third of the dough with breadcrumbs, add the apples and the remaining ingredients. Brush the rest of the dough with melted butter, roll up the strudel and place on a buttered baking tray. Brush with butter and bake until golden.
Temperature: 180°C
Baking time: 35 minutes