Mix the flour, mondamine, baking powder, 125 g sugar and 2 sachets of vanilla sugar, then add 125 g margarine and the two eggs. Use the dough hook of a hand mixer to make a dough. Spread the dough on a greased baking sheet (possibly lined with baking paper). Spread the jam on the dough.
Heat and melt 200 g margarine in a saucepan. Stir in 200 g sugar, 2 packs of vanilla sugar, water and hazelnuts. Spread this mixture onto the dough while it is still warm.
Bake in the preheated oven for approx. 45 minutes at 175 ° C.
Cut into triangles while still warm. Melt the chocolate icing and decorate the triangles with it.