Halve the lime and squeeze it. Mix yoghurt, lime juice and vanillin sugar. Mix cherries, multi-grain flakes, flakes and amaranth in a large bowl.
Peel the bananas and cut them into thin slices. Mix into the muesli. Put the muesli into 4 bowls, spread yoghurt on top and sprinkle with sugar. Decorate with lemon balm.