For the choux buns, boil water with salt, sugar, vanilla sugar and butter. Pour in flour all at once, burn off to form dumplings.
Remove the mixture from the heat, stir in 1 egg, let cool. One by one, stir in the remaining eggs. Pipe wavy stripes (about 10 cm long) on the baking tray lined with baking paper.
Bake for 25 minutes at 225 degrees. For the filling, whip the cream with cream stiffener, add sugar and vanilla sugar to taste.
Cut the finished, cooled slices, fill with vanilla cream, brush the top with icing. For the icing, mix all the ingredients together.