First brown the ground and chopped hazelnuts until they are dry in a pan at a low temperature (as soon as the nuts get color, remove them directly from the plate and continue stirring). Pour roasted nuts into a bowl and set aside.
Beat the butter, vanilla sugar and sugar until frothy. Gradually stir in each egg one at a time. Then add bitter almond oil, grated tonka bean, cinnamon, amaretto and creme fraiche. Mix the flour and baking powder, sift into the dough in 3 stages and beat in. Now pour the roasted nuts into the batter and stir in.
Finally, quickly cut the chilled nut nougat into cubes. Dust the cubes with flour and fold in carefully. Pour into a greased springform pan with a tube base, sprinkled with breadcrumbs, and smooth it out.
Bake at 160 ° (preheated) for approx. 55 - 65 minutes.
Decorate the cooled cake with powdered sugar, icing (amaretto, cinnamon, etc.) or couverture.