Gioconda biscuit: Whip together the almonds, sugar, flour and egg yolks for approximately 15 minutes. Beat the egg whites and sugar until stiff. Gently blend in the egg whites to the rest of the preparation using a spatula. Melt the butter, let cool and add to the mixture. Spread the preparation on parchment paper. Cook at 250 ºC 5–7 minutes. Remove the biscuit from the plaque as soon as it comes out of the oven.
Coffee buttercream: Cook the sugar in 70 g of water until it reaches the small ball degree. Add 1 whipped whole egg and one yolk to the sugar mixture. Whip the mixture until it cools down. Gradually add previously softened butter and continue whipping. The mixture should double in volume and whiten. Add 15 g of coffee dissolved in a small amount of water.
Chocolate ganache: Bring the cream to a boil with the remaining coffee. Blend in the chopped chocolate. Allow to cool.
Combination: Divide the rolled out Gioconda biscuit dough into 3 equal parts. Spread the ganache on a first layer of dough. Cover with the next layer, garnishing with the coffee buttercream. Cover with the last layer. Cool. Chop up the topping chocolate and mix with the cream. Bring to a boil. Glaze the cake.
Traditionally the word "Opera" is written on the cake. Certain pastry chefs would rather cover the cake in black or white chocolate in which musical instruments or notes are imprinted. Others choose an edible gold leaf cover giving the dessert a more "theatrical" touch. Jacques Torres, a star pastry chef at New York's chic Le Cirque restaurant, serves the cake with a small, 10 cm-high chocolate stove. The waiter then takes two tiny chocolate pans from the two "burners" on the stove and pours a fruit sauce directly on the cake.
As we have shown over the preceding months, almost from its beginning opera has inspired culinary creations from the most rustic (Pasta alla Norma ) to the most sophisticated (Semifreddo ). The opera cake was created in the 1960s by the well-known French pastry chef Gaston Lenôtre. The marriage between opera and desserts is a daily reality in a number of great opera houses. At New York's Metropolitan Opera for instance, the well-to-do dine with refinement at the in-house restaurant before the show. At the first bell, the music lovers are careful to reserve their dessert for the first intermission! In the coming months we hope to present desserts created by the chefs there, including those inspired by Diva Renée Fleming and other stars of the lyric stage.