Prepare a baking sheet with a diameter of approx. 8 x 12 inches, grease the bottom thoroughly with butter and sprinkle with flour.
Use a mug with a volume of approx. 10 fl oz. Mix all the loose ingredients in a large bowl. In the second bowl, thoroughly mix the grated apples with cinnamon.
Pour the loose mixture onto the bottom of a greased and floured baking sheet (pour so much that you can't see the bottom of the baking sheet). Layer the apples on top of the dry mixture, which you do not squeeze in hands. Layer the loose mixture again and the apples again. You end it with a loose layer and then just grate butter on top (use a coarse grater).
Bake the cake in a preheated oven. Bake at a temperature of 390 °F / 200 °C for about 40 minutes.