Beat the egg whites for the layer into hard snow with the sugar. Carefully add the flour and stir with a spatula. Mix with the crushed nuts and pour 1/3 of it in an 8 diameter baking dish, covered with baking paper. Use the other 2/3 to bake a total of 3 cake layers in a preheated oven at 320°F (160 °C).
Bake each layer for about 20-25 minutes and cool on a cooking grid. For the cream, beat the eggs with the sugar and add the flour and vanilla. Gradually pour in the pre-boiled milk and stir vigorously. Transfer the cream to the pot where you boiled the milk and stir vigorously until thickened.
Crumble the chocolate and mix it with the hot cream, then leave it to cool. Beat the mascarpone, add the cream and beat very well. In portions, add the mascarpone and cream to the other cooled cream and mix until uniform.
In a suitable oven dish, stick the layers together with the cream and finish the cake off with plenty of cream. Optionally, garnish with chopped nuts or make other decorations.
Leave it in the refrigerator overnight before serving.