First thaw the frozen berries, preferably in the microwave for 5 minutes at 150 W.
Now finely puree the ripe banana piece with a fork, add low-fat quark, water and oil. Mix carefully until you have a homogeneous, creamy emulsion. Add muesli, nuts and cinnamon and stir again briefly. Finally add the berries as a topping.
A healthy breakfast, which should keep you full until noon with only about 512 kcal.