Prepare joconde (almond sponge cake). Preheat oven to 400F (200C). Grease and line with parchment paper two 9x13 inch (23x33cm) baking pan. Sift the almond flour and powdered sugar into a large bowl. Add the whole 5 eggs and mix until the mixture is creamy and fluffy. Incorporate flour. In another bowl whip the egg whites and salt until foamy. Gradually add sugar and continue mixing until stiff peaks form. Fold the whipped whites into the almond mixture and add melted butter. Divide batter evenly into prepared pans. Bake for 8-10 minutes until slightly golden. Cool completely. When completely cooled use a 8 inch (20cm) square ring to cut the sponge cakes into three Prepare coffee syrup . Place the water, sugar and coffee into a small saucepan and bring to boil over medium heat. Set aside to cool completely. Prepare chocolate croustillant. Melt the chocolate over bain-marie. Add Pailleté feuilletine and stir to combine. Spread the croustillant on top of one square sponge cake. Refrigerate to set. Prepare chocolate ganache. Place chocolate into a bowl. Heat cream into a small sauce pan until it starts to boil. Pour over the chocolate. Let sit for 1 minute. Stir until completely melted. Set aside to cool, at room temperature. Prepare coffee buttercream. Mix egg yolks in a heatproof bowl until creamy and light yellow colored. In a small saucepan combine sugar with water and instant coffee and place on medium heat. Using a candy thermometer measure syrup temperature. When it reaches 240 F (115C) pour it gradually over the creamy egg yolks, while mixing continuously. Continue mixing until the mixture is cooled. Gradually add softened butter, mix on low until butter is incorporated and then mix on high speed until smooth and fluffy. Cake assembly. Take the croustillant coated sponge cake layer from the fridge, flip on a serving plate with chocolate croustillant facing down. Brush the sponge cake layer with coffee syrup. Spread half of coffee buttercream. Add another layer of sponge cake, soak well with coffee syrup. Spread the cooled chocolate ganache. Add the last layer of sponge cake and brush well with coffee syrup. Spread the other half of buttercream on top and even the surface using an offset spatula or cake scraper. Cover and refrigerate the cake for at least 2 hours or even overnight. Prepare chocolate glaze. Before preparing the glaze place the chilled cake over a rack placed on a baking sheet lined with parchment paper. Melt the chocolate over bain-marie. Add oil and stir to combine. Pour the glaze immediately over the chilled cake to create a smooth surface. Refrigerate for about 1 hour to set. Using a hot knife cut the edges of the cake and cut the cake in 8 or 10 rectangular pieces. Using the leftover chocolate glaze write “Opera” on each and decorate with gold leaf. Enjoy!