For the coconut cake, first preheat the oven to 170 °C hot air. Pass the powdered sugar through a sieve so that no large lumps remain in the sugar. Cream the sugar with the vanilla sugar, egg yolks and oil. Sift the cornstarch and baking powder into the flour and mix with the coconut milk. Mix the milk mixture with the sugar-oil mixture.Beat the egg whites until stiff peaks form and gently fold into the cake mixture. If you stir too much, you will knock the volume back out of the cake mix and the cake will not be fluffy.
Grease and dust a bundt pan and fill with the mixture. Bake in the oven for about 60 minutes. Afterwards, let the coconut bundt cake cool, brush with a little jam and sprinkle with coconut flakes.