1. Preheat oven to 325 degrees Fahrenheit.
2. Divide dough into two. Roll out half the dough on a well-floured surface and place it on the bottom of a 10 x 16-inch pan, coming up the sides.
3. Sprinkle dough with bread crumbs.
4. In a large bowl, combine apples, sugar, cinnamon, lemon, and vanilla sugar.
5. Add the filling on top of the dough and sprinkle more bread crumbs on top.
6. Roll out remaining dough and place it over the filling. Pinch it together to the bottom half. Brush the top with egg white. Bake for one hour.