Cut the apples peeled or unpeeled into large cubes and place in a baking dish. Fold the juice of one lemon and a little cinnamon into the apples. Preheat the oven to 190 ° C.
Mix the softened butter in a mixing bowl with all the remaining ingredients for the dough, finally add the flakes and knead the dough.
Spread the resulting crumble on the apples and bake for about 25 minutes on the middle rack until it is golden brown.