For meringue: It is best to prepare the meringue a day ahead of time before making cake. I usually prepare the meringue in the morning and let it dry and cool in the oven with the door ajar. Store prepared meringue covered well and away from moisture until ready to use.

Cover a large, flat baking sheet with parchment paper and use an 8-inch round cake pan to draw 2 circles on the parchment paper. Set pan aside and preheat oven to 175 degrees Fahrenheit.

To prepare meringue, place egg whites into a stand mixer bowl (preferably use a heavy duty stand mixer so egg whites reach their optimum consistency). Beat egg whites and sugar on high speed until they reach stiff peaks. Divide the meringue evenly and spread onto prepared parchment paper, using the circles as guides. Use a flat spatula to make sure top and sides are as even as possible.

Place meringue into oven and bake for 8 hours at 175F, until completely dried and crisp. To check doneness, tap lightly on the top in the center of meringue -- it should sound hollow. After 8 hours, turn oven off and leave door ajar, letting meringue cool slowly in the oven. When getting ready to assemble cake, gently remove the meringue off from the parchment paper.

For sponge cake: Preheat oven to 350 degrees Fahrenheit. Line 2, 8-inch round cake pans with parchment paper and set aside. Sift together flour and baking powder. Place eggs and sugar into mixer bowl; whisk on high speed until eggs are thick and pale. Using a fine strainer, slowly dust the flour over the eggs and fold the flour in. Immediately pour cake batter into prepared cake pans, dividing the batter evenly. Bake in preheated oven for 14 to 16 minutes, until cake is golden on top. Remove hot cake layers from pan, invert onto cooling rack and remove parchment paper.

To assemble cake, spread frosting between alternating layers of sponge cake and meringue, placing diced hazelnuts between layers.