For the Christmas Danube Waves with Powidl, cream the room-warm butter with a pinch of salt, vanilla sugar and powdered sugar until fluffy. Separate the eggs and stir the egg yolks into the butter and sugar mixture. Beat the egg whites until firm. Beat the egg whites briefly and gradually add the sugar. Sift the flour with the baking powder and stir into the butter-sugar mixture. Finally, carefully add the beaten egg whites. Put half of the mixture into different bowls and mix some of it with cocoa. Line a baking tray with baking paper and spread half of the mixture. Spread the cocoa half of the batter over the light batter. As soon as the second dough mixture is spread, quickly make small holes in it, e.g. with a wooden spoon style, and fill the Powidl into them. Bake in the oven at hot air (approx.180 degrees) for 25 minutes.
For the cinnamon glaze:Mix warm water with powdered sugar until the desired consistency of the glaze is achieved. If you prefer a thin glaze, use less sugar. If you want the frosting to be nice and thick, stir in more sugar.Stir in cinnamon to taste as well.
Finishing:Spread the cinnamon glaze on the cooled Danishes and allow to set.