Great grandmother Anna's Wartime Apple Cake

The recipe is a bit odd, because the actual cake contains neither butter nor eggs and only very little fat poured over it. The story behind it is that my great grandmother, who was a cook, supposedly made this up during the war. My mother used to make this all the time when I grew up, always taking care to feed me some stories about wartime rationing with it.

I call it “apple cake” rather than “apple pie” because the result is very much like a very moist, heavy sort of sponge cake. It doesn’t need custard or ice cream or cream and it tastes even better cold and doesn't get dry - it's still fine after a few days in the fridge. It yields a lot too, so it'd be very good for some sort of festive occasion, either with tea or coffee, or as a simple and rustic dessert.

2,5 dl sugar (1 cup)
6 dl flour (2.5 cups)
3 dl milk (1.3 cups)
5 teaspoons baking powder
5-8 apples (depending on size)
sugar, cinnamon
butter or margarine according to taste (I’d say about 100 g but the more the tastier - but obviously, you could get away with much less)

1. Peel and slice apples very thinly (remove the seeds and such first of course).
2. Mix sugar, flour and baking powder. Pour the milk a little at the time while stirring. Stir until smooth. It’s going to be not quite like dough, but a lot stickier than when you make ordinary sponge cake or muffins.
3. Prepare an oven-pan (a large one, I used one that was about 35×30 cm – about 11×14 inches) with butter and breadcrumbs. Pour the mixture into the dish.
4. Cover it with layer of apple slices.
5. Pour some sugar and cinnamon on them.
6. Put on another layer of apples. Add more sugar and cinnamon.
7. Finish by pouring the melted butter evenly over the cake.
8. Bake in 225 °C (450 °F) for app 20 min

*Sorry for the poor picture quality; it's an old photo