Opera Cake

🧂 Ingredients

• 6 large egg whites

  at room temperature
• 2 tbsp. 30 grams granulated sugar
• 2 cups 225 grams almond flour
• 2 cups icing sugar

  sifted
• 6 large eggs
• ½ cup 70 grams all-purpose flour
• 3 tbsp. 1½ ounces; 45 grams unsalted butter, melted and cooled
• ½ cup 125 grams water
• ⅓ cup 65 grams granulated sugar
• 1 tablespoon fresh orange juice
• 1 tablespoon almond or vanilla extract
• 1 cup granulated sugar
• 4 large egg whites

  room temperature
• 12 ounces unsalted butter

  room temperature
• ¼ cup fresh orange juice
• 1 teaspoon vanilla extract
• 1 tablespoon orange zest
• 7 ounces white chocolate
• 1 cup plus 3 tablespoons heavy cream

  35% cream
• 1 tablespoon Grand Marnier liqueur
• 14 ounces white chocolate

  coarsely chopped
• ½ cup heavy cream

  35% cream
• 1 -2 drops of orange gel food coloring

Instructions

• 1 JocondeNote: The joconde can be made up to 1 day in advance and kept wrapped at
  room temperature
• 2 Divide the oven into thirds by positioning a rack in the upper third of the oven
  and the lower third of the oven.
• 3 Preheat the oven to 425°F. (220°C).
• 4 Line two 12½ x 15½- inch (31 x 39-cm) jelly-roll pans with parchment paper and
  brush with melted butter.
• 5 In the bowl of a stand mixer fitted with the whisk attachment (or using a
  handheld mixer), beat the egg whites until they form soft peaks. Add the
  granulated sugar and beat until the peaks are stiff and glossy. If you do not
  have another mixer bowl, gently scrape the meringue into another bowl and set it
  aside.
• 6 If you only have one bowl, wash it after removing the egg whites or if you have
  a second bowl, use that one. Attach the paddle attachment to the stand mixer (or
  using a handheld mixer again) and beat the almond flour, icing sugar and eggs on
  medium speed until light and voluminous, about 3 minutes.
• 7 Add the flour and beat on low speed until the flour is just combined (be very
  careful not to overmix here!!!).
• 8 Using a rubber spatula, gently fold the meringue into the almond mixture and
  then fold in the melted butter. Divide the batter between the pans and spread it
  evenly to cover the entire surface of each pan.
• 9 Bake the cake layers until they are lightly browned and just springy to the
  touch. This could take anywhere from 5 to 9 minutes, depending on your oven.
  Place one jelly-roll pan in the middle of the oven and the second jelly-roll pan
  in the bottom third of the oven.
• 10 Put the pans on a heat-proof counter and run a sharp knife along the edges of
  the cake to loosen it from the pan. Cover each with a sheet of parchment or wax
  paper, turn the pans over, and unmold.
• 11 Carefully peel away the parchment, then turn the parchment over and use it to
  cover the cakes. Let the cakes cool to room temperature.
• 12 Simple Syrup(Note: The syrup can be made up to 1 week in advance and kept
  covered in the refrigerator.)
• 13 Stir all the syrup ingredients together in the saucepan and bring to a boil.
• 14 Remove from the heat and let cool to room temperature.
• 15 Buttercream:Put the sugar and egg whites in the medium heatproof bowl and fit
  the bowl over a plan of simmering water. Whisk the mixture constantly over
  medium heat, until it feels hot to the touch, about 3 minutes. The sugar should
  be dissolved, and the mixture will look like shiny marshmallow cream. Remove the
  bowl from the heat.
• 16 Working with the whisk attachment, beat the meringue on medium speed until it is
  cool, about 5 minutes. Switch to the paddle attachment and add the butter a
  stick at a time, beating until smooth. Once all the butter is in, beat the
  buttercream on medium-high speed until it is thick and very smooth, 6-10
  minutes. During this time the buttercream may curdle or separate – just keep
  beating and it will come together again.
• 17 On medium speed, gradually beat in the orange juice, waiting until each addition
  is absorbed before adding more, and then beat in the vanilla. You should have a
  shiny velvety smooth buttercream. Stir in orange zest. Press a piece of plastic
  against the surface of the buttercream and set aside briefly.
• 18 White Chocolate Ganache Mousse:(Note: The mousse can be made ahead and
  refrigerated until you’re ready to use it.)
• 19 Melt the white chocolate and the 3 tbsp. of heavy cream in a small saucepan.
• 20 Stir to ensure that it’s smooth and that the chocolate is melted. Add the
  tablespoon of liqueur to the chocolate and stir. Set aside to cool completely.
• 21 In the bowl of a stand mixer, whip the remaining 1 cup of heavy cream until soft
  peaks form.
• 22 Gently fold the whipped cream into the cooled chocolate to form a mousse.
• 23 If it’s too thin, refrigerate it for a bit until it’s spreadable.
• 24 If you’re not going to use it right away, refrigerate until you’re ready to use.
• 25 Orange GlazeNote: It’s best to make the glaze right when you’re ready to finish
  the cake.
• 26 Melt the white chocolate with the heavy cream. Whisk the mixture gently until
  smooth.
• 27 Let cool for 10 minutes and then pour over the chilled cake. Using a long metal
  cake spatula, smooth out into an even layer.
• 28 Place the cake into the refrigerator for 30 minutes to set.
• 29 Assembly(Note: The finished cake should be served slightly chilled. It can be
  kept in the refrigerator for up to 1 day).
• 30 Line a baking sheet with parchment or wax paper.
• 31 Working with one sheet of cake at a time, cut and trim each sheet so that you
  have two pieces (from each cake so you’ll have four pieces in total): one
  10-inch (25-cm) square and one 10 x 5-inch (25 x 12½-cm) rectangle.
• 32 Place one square of cake on the baking sheet and moisten it gently with the
  flavoured syrup.
• 33 Spread about one-half of the buttercream over this layer.
• 34 Top with the two rectangular pieces of cake, placing them side by side to form a
  square. Moisten these pieces with the flavoured syrup.
• 35 Spread the remaining buttercream on the cake and then top with the third square
  of joconde. Use the remaining syrup to wet the joconde and then refrigerate
  until very firm (at least half an hour).
• 36 Prepare the ganache/mousse (if you haven’t already) and then spread it on the
  top of the last layer of the joconde. Refrigerate for at least two to three
  hours to give the ganache/mousse the opportunity to firm up.
• 37 Make the glaze and after it has cooled, pour/spread it over the top of the
  chilled cake. Refrigerate the cake again to set the glaze.
• 38 Serve the cake slightly chilled

Nutrition Info