Irresistible Opera Cake
Opera cake is a French dessert noted for its delicate and tense flavour layers. Combine your flour and sugar then set aside. In a stand mixer, beat egg whites and one-third of the sugar on high speed until it’s fluffy transfer it to a clean bowl. Combine the powders with the egg yolks and beat them for about five minutes then add in the melted butter and continue beating the mixture. Gently fold one-third of the meringue into the mixture and then pour the remaining meringue and mix them until combined. Do not overwork on this butter or it will deflate.
You will need two 13 by 18 baking trays, spread the batter on the tray evenly and bake them at 450 degrees Fahrenheit for about 7 minutes. Once baked, remove from the oven and let them cool. Divide each cake sheet into 9 by 12-inch rectangles and coat the surface of the bottom sponge with melted chocolate. Cover immediately with parchment paper and flip over with the chocolate side down then refrigerate the cake. Get your coffee syrup ready and let it cool, fr the coffee buttercream, boil milk, sugar and coffee beans to a simmer. Meanwhile, beat egg yolks and sugar then add the milk mixture into the yolk and sugar mixture then place it over the heat for a few minutes before sieving and discarding the coffee beans.
Beat the sieved mixture on high speed until cooled to room temparature then add on butter and whip until creamy and fluffy. To assemble the cake, remove it from the fridge and then brush it generously with the coffee syrup, making sure it is completely soaked. Carefully spread one-third of the buttercream over the surface of the cake then cover with the second sponge and soak it with the coffee syrup. Spread the chocolate ganache evenly over the second cake and then place the last sponge cake at the top and soak it with coffee syrup.
Chill the cake until firm and then spread the last coffee buttercream layer. Let it cool then spread the chocolate glaze over the cake until the top is completely covered with the ganache. Chill the opera cake in the fridge until ready then slice it.
Ingredients;
For almond sponge cake;
- 3 tablespoons cake flour, sifted after measuring, plus additional for dusting pan
- 2 whole large eggs at room temperature for 30 minutes
- 1 cup almond flour (3 1/2 oz) or 2/3 cup blanched whole almonds
- 1/2 cup confectioners sugar, sifted after measuring
- 2 large egg whites at room temperature for 30 minutes
- 1/8 teaspoon cream of tartar
- 1/8 teaspoon salt
- 1 tablespoon granulated sugar
- 2 tablespoons unsalted butter, melted, foam discarded, and butter cooled
For coffee syrup;
- 1 teaspoon instant espresso powder
- 1/2 cup plus 1 tablespoon water
- 1/2 cup granulated sugar
- 1/4 cup Cognac or other brandy
For coffee buttercream;
- 2 teaspoons instant espresso powder
- 1/4 cup plus 1 tablespoon water
- 6 tablespoons granulated sugar
- 2 large egg yolks
- 1 stick (1/2 cup) unsalted butter, cut into 1/2-inch cubes and softened
For chocolate glaze;
- 3/4 stick (6 tablespoons) unsalted butter
- 7 oz fine-quality bittersweet chocolate (not unsweetened; preferably 70 to 71% cacao), coarsely chopped
Instructions;
Make the sponge cake;
- Put oven rack in middle position and preheat oven to 425°F.
- Butter the baking pan, then line the bottom with a sheet of parchment or wax paper, leaving a 1-inch overhang on short sides, and generously butter paper.
- Beat whole eggs in a large bowl with a handheld electric mixer at high speed until eggs have tripled in volume and form a ribbon when beaters are lifted 2 to 3 minutes.
- Reduce speed to low, then add almond flour and confectioner sugar and mix until just combined.
- Resift cake flour over the batter and gently fold in.
- Beat egg whites in a bowl with cleaned beaters at medium speed until foamy.
- Add cream of tartar and salt and beat until whites just hold soft peaks.
- Add granulated sugar, then increase speed to high and beat until whites just hold stiff peaks.
- Fold one-third of the whites into the almond mixture to lighten, then fold in the remaining whites gently but thoroughly.
- Fold in butter, then pour batter evenly into the baking pan, spreading gently and evenly with an offset spatula and being careful not to deflate.
- Bake until very pale golden, 8 to 10 minutes, then cool in a pan on a rack for 10 minutes.
- Loosen the edges of the cake with a spatula, then transfer the cake (on paper) to a cutting board.
- Cut the cake into strips and squares. Trim the outside edges slightly, then carefully peel the paper from strips and squares and set it back on the paper.
Make the coffee syrup;
- Stir together espresso powder and 1 tablespoon water until powder is dissolved.
- Bring sugar and remaining 1/2 cup water to a boil in a 1- to 2-quart heavy saucepan, stirring until sugar is dissolved.
- Reduce heat and simmer syrup, without stirring, for 5 minutes. Remove from heat and stir in the coffee mixture.
Make coffee buttercream;
- Stir together espresso powder and 1 tablespoon water until powder is dissolved.
- Bring sugar and remaining 1/4 cup water to a boil in a very small heavy saucepan, stirring until sugar is dissolved.
- Boil, without stirring, washing down any sugar crystals on the side of the pan with a pastry brush dipped in cold water until syrup registers 238°F on the thermometer.
- While syrup boils, beat yolks in a large bowl with cleaned beaters at medium speed for 1 minute.
- Add hot syrup to yolks in a slow stream, beating, then add coffee mixture and beat until completely cool, 3 to 5 minutes.
- Beat in butter, 1 piece at a time, and beat until thickened and smooth.
Make glaze;
- Melt butter and all but 2 tablespoons of chopped chocolate in a double boiler or in a metal bowl set over a saucepan of barely simmering water, stirring occasionally, until smooth.
- Remove the top of a double boiler and stir in the remaining 2 tablespoons of chocolate until smooth, then cool the glaze until room temperature but still liquid.
Assemble cake;
- Put 1 cake square on a plate, then brush generously with one-third of the coffee syrup.
- Spread half of the buttercream evenly over top with a cleaned offset spatula, spreading to the edges.
- Arrange both cake strips side by side on top of the first layer, then brush with half of the remaining coffee syrup.
- Spread half of the glaze evenly over the top, spreading just to the edges.
- Top with remaining cake square and brush with remaining coffee syrup.
- Spread the remaining buttercream evenly over top, spreading just to the edges.
- Chill cake until buttercream is firm, about 30 minutes.
- Reheat the remaining glaze over barely simmering water just until shiny and spreadable, about 1 minute.
- Pour all but 1 tablespoon glaze over the top layer of cake and spread evenly just to the edges.
- Scrape the remaining tablespoon of glaze into a sealable plastic bag and twist the bag so the glaze is in 1 corner.
- Chill cake until glaze is set, about 30 minutes, then trim edges slightly with a sharp serrated knife.