Beat the butter with sugar, salt and vanilla sugar until frothy, gradually stir in the eggs vigorously; Add hazelnuts and lemon and orange peel or aromas; dose carefully, the cake should taste slightly like orange, but the aromas should not be predominant.
Mix the flour with cornstarch and baking powder and sieve, gradually adding to the egg, butter and sugar mixture.
Put the dough in a greased baking pan dusted with flour and bake at 180-200 degrees for 40-50 minutes.
Tip: the cake can also be made with whole wheat flour, then please only use 150 g. The cake is also easy to bake in silicone molds; In the case of very filigree shapes, you should still grease and flour.