Grind oatmeal in a blender to a state of flour. Pour the oatmeal into a wide bowl.
Add sifted wheat flour, vanilla sugar and ground walnuts. Mix.
Beat the softened butter with a mixer with half the sugar until an absolutely homogeneous white mass is obtained. While continuing to beat, carefully pour in the eggs.
Mix the remaining sugar in a saucepan with 2 tbsp. l. water. Cook until the syrup turns light brown. Remove from heat, add 1 more tbsp. l. water, mix and add to the egg mixture. To stir thoroughly. Then, continuing to stir, add a mixture of oatmeal and wheat flour. Knead the dough.
Preheat the oven to 180°C. Put the finished dough on a floured work surface and roll it into a 1 cm thick layer. Using culinary notches, cut out cookies of various shapes from the dough. Lay on a baking sheet covered with oiled parchment, bake in the oven for 20 minutes.
Cover the surface of hot cookies with icing sugar or melted chocolate. Sprinkle with oatmeal.