Beat the sugar and eggs until frothy, then add the vanilla yogurt, vanilla sugar, flour and baking powder. Stir in the melted butter. Finally cut the rhubarb into approx. 2 cm pieces and halve the strawberries, fold in everything and spread on a baking sheet. Bake at about 160 ° C for about 30 minutes.
Variants: Instead of strawberries and rhubarb, you can use 2 pears, 4 apples, almonds and cinnamon outside of the season, and the cake is also totally delicious then.