Mix the butter, sugar, salt and vanilla sugar into a creamy white foam. Then stir in the 250 g flour with 50 g cornstarch. Fill this dough into a piping bag with a star nozzle and spray it on a greased sheet (or use baking paper or baking foil) in the same size as a flame.
Bake at 190 ° C for about 10 minutes (depending on the oven).
Remove from the baking sheet, let it cool down, then stick together with jelly or Nutella of your choice. Dip the outer sides in chocolate glaze or melted couverture, allow to dry and store in a cool, tightly closing jar.