Giant Apple Strudel

Method

1. Grease a large baking sheet and set aside. Put apples, butter, raw sugar and sultanas into a large pot. Cover and cook over low heat, stirring occasionally, until the apples are tender.
2. Add the mixed cornstarch to the apples and cook for another 5 minutes, stirring constantly, until the mixture thickens. Remove from heat and let cool.
3. Roll out the dough on a lightly floured surface to a 40 cm square. Cut out a large triangle (short side 33 cm, long side 40 cm). Sprinkle with cold water and place the dough triangle on the prepared baking sheet. Preheat the oven to 220°C.
4. Spread the apple mixture over the pastry, leaving a 3 cm border. Roll out the remaining dough to a slightly larger triangle and place it over the filling. Press the dough edges together firmly and cut straight with a sharp knife, then press together again with your fingertips.
5. Brush the dough surface with whisked egg and sprinkle with Demerara sugar. Make three small holes in the dough to allow steam to escape.
6. Bake the apple turnover in the preheated oven for 35-45 minutes, until the dough has risen and is golden brown. If the dough becomes too dark, cover loosely with aluminum foil. Cut into 12 pieces and serve warm or cold.