Opera Cake

Ingredients:

Viennese sponge cake

• 2 large eggs at room temperature, whites separated from yolks
• 1 large whole egg, room temperature
• 1/4 cup + 2 tablespoons sugar
• 2/3 cup ground almonds
• 6 tbsp. flour for baking and cakes, sifted

Ganache for filling and glaze

• 1 cup whipping cream
• 240 g dark chocolate, chopped
• 60 g of chocolate glaze or chocolate chips
• 2 tablespoons of vegetable oil

Coffee buttercream

• Whites of 2 eggs, room temperature
• 2 tbsp. + 0.5 tbsp. sugar
• 1 cup (230 g) butter, room temperature
• 1 tbsp coffee extract (or 1 tbsp very strong espresso, chilled)
• 1 tsp vanilla extract

Coffee syrup and cake assembly

• 0.5 cups of hot coffee
• 3 tablespoons of sugar
• 45 g melted chocolate glaze
• 6 coffee beans in chocolate glaze

Preparation:

1. Preheat oven to 200°C and line a 27x42cm loaf tin with parchment paper.
2. Whisk 2 egg yolks and a whole egg with 1/4 cup sugar until thick and pale, and the mixture runs off the whisk in a ribbon. In a separate bowl, combine the ground almonds and flour.
3. In another bowl, beat 2 egg whites until foamy, then slowly add the remaining 2 tablespoons sugar, whisking until soft peaks form. Fold the beaten whites into the yolks in 2 additions, then fold in the almond mixture. Pour the batter evenly into the prepared pan, making sure it lies flat (the batter will form a very thin layer). Bake for about 8 minutes, until golden brown, then cool. The cake may become slightly dry as it cools—this is normal.
4. Ganache: Heat the cream until just above the boil, and pour it over 240g of chopped chocolate. Let it sit for a minute, then gently stir with a spatula, working from the center outward in a circular motion until the chocolate is completely melted and the ganache is smooth. Let it cool to room temperature.
5. Butter cream: Place the egg whites in a bowl and whisk with 2 tablespoons of sugar until foamy. Place the remaining 1/2 cup of sugar in a small saucepan, add 2 tablespoons of water, and bring to a full boil over high heat. Cook until the sugar reaches 115°C (225°F) on a syrup thermometer. With the mixer on medium speed, carefully fold the hot syrup into the whipped whites, pouring it down the side of the bowl (to prevent splashing). Then increase the mixer speed and whisk until the whites cool to room temperature, about 4 minutes. Beat in the butter, a few pieces at a time. The custard may seem to curdle as you add the butter. Don't worry, just continue adding the butter and whisking until smooth. You don't want to overbeat the custard. Stir in the coffee extract (or espresso) and vanilla. Use custard at room temperature.
6. Coffee syrup: Stir sugar into coffee until completely dissolved.
7. Assembly: Remove the cake layer and cut it into three rectangles (approximately 15 x 27 cm). Brush one side of the cake layer with melted chocolate and let it set (you can refrigerate it for 3 minutes). Then place the cake layer, chocolate side down, on a cake stand or plate. Brush the top of the cake layer with coffee syrup and cover with half of the buttercream. Place the second cake layer on top, brush it with syrup, and spread 2/3 of the ganache (cooled but spreadable). Place the last cake layer on top of the ganache, brush it with syrup and the remaining buttercream (or you can reserve about 1/4 cup of the frosting for decoration).
8. Ganache glaze: Warm the remaining third of the ganache, adding the chocolate glaze and vegetable oil. Stir until smooth. Spread the glaze over the cake and spread it evenly over the entire surface (except the sides). Refrigerate the cake for about 2 hours.
9. Before serving, trim the sides of the cake to expose the neat layers and cut it into 6 rectangles (it's easier to cut with a hot, dry knife). If desired, decorate the cake by piping a small amount of frosting from a pastry bag and placing a frosted coffee bean on top.