In a bowl whisk the flour with sparkling water, oil, sugar, eggs and the vanilla sugar until frothy. Spread the batter onto a lined baking tray. Bake in the preheated oven at 200°C for 25-30 minutes until the cake base is golden. Allow to cool.Drain the cherries and keep the juice.

Whip the cream until stiff. Fold in the Crème fraîche and the sour cream. Spread the cake base with the cream. Dust with cinnamon and arrange the cherries on top.

Mix the cornstarch with some of the cherry juice. Bring the remaining juice to a boil, add the cornstarch mixture and cook until thickened.

Spread the glaze over the cherries, let cool down and refrigerate the cake for 2-3 hours before serving.