Opera Cake

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INGREDIENTS

  • Almond Sponge (Jaconde)
  • 4 large egg whites (120g), at room temperature
  • 20 grams granulated sugar
  • 150 grams ground blanched almonds
  • 150 grams confectioners sugar, sifted
  • 4 large whole eggs
  • 47 grams all-purpose flour
  • 30 grams unsalted butter, melted and cooled

Chocolate Sponge

  • 4 ounces good quality semi-sweet chocolate- I used callebaut
  • 1/2 cup cold water
  • 4 whole eggs, warmed*
  • 1/2 cup granulated sugar
  • 3/4 cups cake flour
  • *warm eggs by placing them in a bowl with hot water for 5 minutes.

Espresso Syrup

  • 1/2 cup water
  • 1/3 cup sugar
  • 2 tablespoons instant espresso powder
  • 1 ounce brandy or congac (optional)

Chocolate Ganache

  • 6 ounces high quality bittersweet chocolate, such as callebaut
  • 3/4 cup heavy cream

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Espresso Swiss Meringue Buttercream

  • 200 grams egg whites
  • 325 grams granulated sugar
  • 2 cups unsalted butter (4 sticks or 16 ounces), at room temperature  but slightly cool, cut into cubes
  • 1 tablespoon pure vanilla extract
  • 2 tablespoon instant espresso powder dissolved in 1 tablespoon boiling water
  • pinch of salt

Chocolate Glaze

  • 4 ounces bittersweet chocolate, chopped
  • 1/2 tablespoon corn syrup
  • 1/4 cup butter (1/2 stick or 2 ounces), cubed

INSTRUCTIONS

To make Almond Sponge

  • Preheat oven to 350 degrees F. Grease one 9 inch round cake pan with butter and cover with parchment.
  • In a clean dry mixer bowl fitted with whisk attachment, beat egg whites until they form soft peaks. Add the granulated sugar and beat until the peaks are stiff and glossy. Gently scrape the whites into another bowl and reserve.
  • In the mixer bowl fitted with the paddle attachment, beat the almonds, confectioners sugar and whole eggs on medium speed until light, and volume has increased, about 3 minutes. Add the flour and mix on low speed just until incorporated. Using a rubber spatula gently fold the meringue into the almond mixture, then fold in the melted butter. Pour into the prepared pan.
  • Bake cake for about 30-35 minutes until the top is golden brown, and toothpick inserted comes out clean. Let cool in pan for 10 minutes, then transfer to a cooling rack and allow to come to room temperature. The cake can be made 1 day ahead and wrapped in plastic wrap and kept at room temperature.

For the Chocolate Sponge

  • Preheat oven to 350 degrees F. Butter and flour 1 9 inch round cake pan.
  • Combine the chocolate and water in a small saucepan and heat the mixture over low heat while stirring for about 5 minutes, or until mixture thickens to consistency of smooth pudding. Remove from heat.
  • In a stand mixer fitted with whisk attachement, beat the eggs and sugar on high speed for about 10 to 12 minutes, or until it has quadrupled in volume and is at the ribbon stage. (When the beater is lifted and the mixture falls in a wide band on the surface and remains for 5 seconds without dissolving)
  • Using a rubber spatula fold the chocolate mixture into the eggs while sifting the flour over. (I.e. fold the chocolate, add a bit of flour in, fold, add more flour) until the flour is no longer visible.
  • Pour the batter into the prepared pan. Bake for about 25 minutes, or until a toothpick inserted comes out clean.
  • Let the cake cool in the pan for 10 minutes. Run a small knife around the edges to release from the pan and cool on a wire rack until at room temperature. Wrap with plastic wrap and keep at room temperature for 1 day.
For the Espresso Syrup
  • In a small saucepan combine the water, sugar, and instant espresso powder and bring to a boil until everything is dissolved. Cool. Cover and refrigerate for up to 1 week.

For the Chocolate Ganache

  • Place the chopped chocolate in a heatproof bowl.
  • In a small saucepan over medium high heat, bring the heavy cream to a simmer (do not boil). Remove from heat and pour over the chocolate. Let the mixture sit for about 10 minutes. Slowly whisk the mixture until smooth. Let the mixture cool overnight covered.
  • Optional:  You can whip the chocolate ganache for a lighter middle layer
  • Using a handheld mixer whisk the set mixture at high speed until light and airy- about 3 to 5 minutes. It will look lighter in colour (like milk chocolate)

For the Espresso Swiss Meringue

  • In a clean bowl of an electric mixer, combine the egg whites and sugar. Place over a pot of simmering water. Whisk constantly until a candy thermometer reaches 140 degrees F, or when the you take the mixture between two fingers and the sugar has completely dissolved and the eggs are hot. Remove from heat.
  • With a stand mixer, whisk the mixture on medium high speed until the meringue is thick, glossy, and the bottom of the bowl is cool. (it should not feel warm). about 15 minutes.
  • With the mixer on medium low speed begin adding the butter, one cube (about 1 tablespoon) until incorporated. Keep mixing until the the buttercream has thickened and is silky smooth. If the buttercream curdles, keep mixing until it is smooth.
  • Switch to the paddle attachment and at low speed, add the vanilla extract, espresso mixture, and salt until incorporated. Increase speed to medium high and beat for 3 to 5 minutes to remove air bubbles.
  • Storage: Cover and keep in an airtight container overnight. Alternatively it may be kept in refrigerator up to one week- bring back to room temperature and rewhip for 5 minutes. May also be frozen for up to 6 months- leave on counter overnight to thaw and rewhip for 5 minutes with paddle attachment of an electric mixer.

For the Chocolate Glaze

**make this after your cake is covered with the buttercream and has been refrigerated

  • Place chopped chocolate, corn syrup, and butter in a heatproof bowl. Place over a pot of simmering water. Using a heatproof spatula, stir until all components are melted and fully incorporated. Remove from heat and set aside for 3 to 5 minutes. If glaze cools too much, replace over pot of simmering water to heat back to spreading consistency.

ASSEMBLY

  • Slice each sponge cake in half. Take one chocolate layer and brush the top completely with the espresso syrup.  Evenly spread about 1 cup of the espresso buttercream on the layer.
  • Top with one layer of the almond sponge cake. Brush the top of the layer  completely with the espresso syrup. Evenly spread all of the chocolate ganache on the layer.
  • Top with another layer of almond sponge cake and brush the top completely with the espresso syrup. Evenly spread about 1 cup of the espresso buttercream.
  • Top with the last chocolate cake layer. Cover the top and sides with the remaining espresso buttercream. I prefer to use an offset spatula to cover and then a bench scraper dipped in hot water and wiped with a clean cloth to smooth the sides.
  • Refrigerate the cake until the buttercream is cold, and not soft to the touch. About 30 minutes or more.
  • When the cake is cold, make the chocolate glaze. Let the glaze cool for no longer than 3 to 5 minutes.
  • Slowly pour the chocolate glaze onto the top centre of the cake. Quickly using an offset spatula spread the glaze evenly and smoothly on the top of the cake, allowing some of the glaze to pour over the sides of the cake.  Because the glaze is hot it's important to work swiftly and gently in order for the glaze not to mix into the buttercream, ensuring a clean glaze.