Preheat the oven to 200 degrees F.

Line 2 large baking sheets with aluminum foil. Using a plate or other round object, trace three 8-inch circles onto the foil to use as templates for piping meringue. Set aside.

Place the egg whites in a large mixing bowl and beat with an electric mixer on medium speed until foamy. While continuing to beat, add the granulated sugar 1 tablespoon at a time. Increase the mixer speed to medium-high and whip until stiff, glossy peaks form, about 5 minutes. Using a large rubber spatula, gently fold in 1 cup sifted powdered sugar, the toasted walnuts and hazelnuts.

Place the meringue in a pastry bag fitted with a plain tip and pipe the meringue onto the foil in a spiraling pattern so that the entire circle is covered with meringue. Repeat with remaining meringue so that you have 3 piped meringue circles.

Bake the piped meringue circles for 3 hours, or until crispy but not colored. If the meringue begins to color and seems crisp, turn off the oven and leave the meringue layers in the oven to continue drying out as the oven cools. Once the oven is cool, remove the baking sheets from the oven and carefully remove the meringue circles from the foil. Set aside until ready to assemble the cake. (Alternately, you can bake the meringues until almost totally crispy, turn off the oven and leave them to dry as the oven cools.)

In a mixing bowl combine the cubed pound or sponge cake with 1/3 cup of the Frangelico and toss to evenly distribute the liqueur. Set aside.

In a chilled, large mixing bowl, whip the heavy cream to soft peaks. Add the 2 tablespoons powdered sugar and remaining 1 1/2 tablespoons Frangelico and continue beating until the cream almost forms stiff peaks. Remove 1/3 of the whipped cream and set aside. Add the sponge cake cubes to the remaining whipped cream and, using a large spatula, gently fold together. Be careful not to over whip or over fold the cream – it will get stiff and begin to turn to butter.

When ready to assemble the cake, place a small amount of the whipped cream on the center of a cake plate and use this to anchor 1 of the crisp baked meringue circles. Place 1/2 of the cake-whipped cream mixture on the top of this meringue circle and spread evenly over the meringue. Top with a second meringue circle and repeat with the remaining cake-whipped cream mixture. Finally, top with the remaining meringue circle and press lightly. Place the whipped cream in a pastry bag fitted with a star tip and pipe stars or rosettes decoratively over the entire surface of the meringue circle. Spread the coarsely chopped walnuts and hazelnuts evenly over the top of the cake, and refrigerate for 2 hours before serving.