Preheat oven to 125 degrees C. Line three baking trays with baking paper. With a pencil draw 5 circles 22cm in diameter on the baking paper. It is best to trace around a cake tin or large saucepan.
In a large clean bowl whisk the egg whites until soft peaks form. Gradually add the white sugar and beat until stiff peaks form.
Sift together the icing sugar, cinnamon and cornflour then toss them together with the ground hazelnuts. Carefully fold them into the egg white mixture.
Divide the mixture evenly between the 5 circles and spread the meringue out to the edge of the drawn circle.
Bake for 3 to 4 hours in the preheated oven until the meringue is completely dried out. Cool on wire racks.
Melt the chocolate over a boiling saucepan until smooth. Spread over baking paper into a 30x22cm rectangle. When the chocolate is set cut the rectangle crosswise into 10-2cm strips. Cut 8 of the strips into thirds. Cut the remaining strips into fourths. Set aside.
To make the filling whip the cream with the 1 tablespoon of icing sugar until stiff. Spread whipped cream over all of the meringue layers. Using one of your prettiest plates, stack the layers on top of one another. Use 2/3 of the remaining whipped cream to spread around the outside edge of the cake. Put the rest of the whipped cream into a pastry bag and pipe rosettes around the edge. Place the 24 long chocolate strips vertically around the sides of the cake. Arrange the remaining pieces of chocolate on the top in the design of your choice. Dust the cake with cocoa powder for a dramatic finish, and serve as soon as possible, as the meringue will soak up moisture from the whipped cream.