Peel and core the apples. Cut into slices ¼ in/0.6 cm thick and toss with the raisins and cinnamon sugar.
Toss the bread crumbs with 2 oz/60 g of the butter.
Cover a work surface with a large linen cloth and dust the cloth with bread flour. Divide the dough in half; set one portion aside, covered. Roll the other portion into a rectangle 12 by 18 in/30