Soak gelatine in cold water. Mix powdered sugar, vanilla sugar, yogurt, lemon zest and egg yolks with a mixer. Squeeze out gelatine, let it melt in warmed Cointreau and mix into the yoghurt mixture. Whip the cream until stiff.
Fold whipped cream into yogurt mixture and refrigerate for about 3 hours. Rinse, clean and crush the strawberries.
Season with powdered sugar and Cointreau. Clean and halve strawberries for garnish, cut kiwi into slices.
Arrange a sauce level on plates. Cut out dumplings from the yogurt mixture and place 3 of each on the fruit layer. Garnish with strawberries, kiwi slices and mint.
Tip: The higher the fat content of the yogurt, the more aromatic and creamy the result!