Soak the oatmeal in the milk with cinnamon overnight. The next morning, coarsely grate a large apple (for allergy sufferers: peel it beforehand!) And fold it into the oat flakes with the yoghurt. Then place the muesli in a microwave-safe dish at 600 watts in the microwave for 3-4 minutes. Stir in between.
I myself am allergic to various (raw) fruits, so I tried it once and there was no allergic reaction, it also tastes really great and is filling for a long time.