How to cook
Beat the egg whites and sugar to snow. Gradually add the flour, hazelnuts and stir well once again. Put baking paper in a 10″ (26 cm) diameter baking form. Divide the mixture into 3 and bake 3 cake layers. Bake in a preheated 356°F (180 °C) oven. Don't bake them too long!
Leave them to cool, while you prepare the yellow cream. Beat the yolks, sugar and flour in half the milk. Leave the rest of the milk on the stove to heat up. Remove from the stove and add the egg mixture in a thin trickle. Return to the stove and turn it down to low. Don't stop stirring until you get a very thick cream.
Don't worry if you get lumps. Once the cream thickens, remove from the stove and add the vanilla. Leave it to cool. Beat the butter to fluffy snow and add it to the egg mixture. Beat with a mixer until you get a smooth cream. Cover it with foil and put it in the fridge to harden.
Caramelize the sugar to an amber color. Put the chopped hazelnuts onto baking paper and pour the caramel over them. Once it hardens, break it into small pieces.
Beat the cream with the powdered sugar and add the caramel. Assemble the cake in cake ring.
The order is as follows: cake layer, yellow cream, white cream and repeat in that order. Leave the cake in the fridge for a few hours and then remove the ring. Decorate the cake with crumbled caramel or caramelized hazelnuts.
Source: Veronika Shketieva.