Add the flour mixed with baking powder. Beat the mixture with a mixer until smooth.
Grate the apples on a coarse grater, leave them for 10 minutes, then drain the liquid from the apples with your hands. Add the grated apples to the mixture. You no longer need a mixer, just take a spatula or spoon and mix well.
Grease a baking tray with butter to prevent the cake from sticking at the end. Pour the mixture into the baking tray and level it evenly.
Place the tray in an oven preheated to 180 degrees for 25 minutes.
If you wish, you can sprinkle powdered sugar on the baked cake.