Cake:
6 eggs
1 cup sugar
2 tsp grated lemon peel
2 1/2 cups ground hazelnuts
2 tbsp dry bread crumbs
1 tsp baking powder
Filling:
2 cups heavy cream, whipped
1/2 cup sugar
1/2 cup ground hazelnuts
Frosting:
2 egg yolks
2 tbsp sugar
1/4 butter, softened
2 squares of semisweet chocolate, melted
1 tbsp nicely chopped hazelnuts
Making the Cake:
Separate eggs and put the whites into large bowl of electric mixer. Place yolks in a small bowl. Let the egg white warm up to room temperature. Preheat oven to 350 F. Line 2 8-inch round cake pans with parchment paper. With mixer at high speed, beat the egg whites until soft peaks form. Gradually beat in 1/2 cup sugar, beating until you reach moist stiff peaks. With same beaters, beat the yolks until thick and light. Gradually beat in the remaining 1/2 cup sugar. Stir lemon peel, hazelnuts, bread crumbs and baking powder into egg yolks and mix well. With mixer on low speed, beat the yolk mixture into the egg whites, just until combined. Pour batter into prepared pans and bake for 30 minutes, or until cake springs back when touched. Cool in pans on rack.
Making the Filling:
Combine all the filling ingredients and mix well.
Making the Frosting:
Beat egg yolks and sugar until thick and light. Add the butter and chocolate and beat until smooth.
Gently remove the cooled cake layers from the pans. Split each of the cakes crosswise, creating a total of four layers. Using 2/3 of the filling, spread between each layer. Frost the top of the later cake with the frosting mixture. use the rest of the filling mixture to cover the sides of the cake. Sprinkle the top with chopped hazelnuts and refrigerate for at least one hour before serving.