Cut the apple into small cubes. Then bring the water to the boil, add the raisins, vanilla sugar and a pinch of cardamom, simmer for about 2 minutes.
Now add the apple cubes and simmer until the apple is a little soft. Then add the oat or rice flakes and simmer, stirring constantly, until the whole thing is a porridge.
You can now add cinnamon and maple syrup as you wish. Finally, all you have to do is serve it!