First put the low-fat quark in a bowl and stir until smooth with a mixer or in a food processor. Whip the cream, add the vanilla sugar and whip the cream until stiff. Stir 1 pinch of vanilla and 1 teaspoon of lemon zest into the quark. Then carefully fold in the cream.
Carefully wash the fruits and pat dry.
Then serve in four glasses. At the bottom one tablespoon of muesli then the quark mass, fruits again quark mass and then a raspberry and a little lemon zest as a decoration. Then place in the refrigerator for at least 15 minutes.