Mix the low-fat quark with the lemon juice, lemon zest, vanilla powder and half a tablespoon of honey and add enough mineral water to achieve the creaminess you want.
Wash the plums or plums, cut in half, stone and cut into wedges.
Divide the quark mixture into two deep plates and sprinkle with the oat flakes. Spread the plums on top and drizzle with the rest of the honey.
Depending on the season, this muesli can be varied in many ways: in winter with oranges, in spring with strawberries and in summer with cherries.