Opera cake with coffee cream and chocolate glaze

Ingredients:

Almond sponge cake

• 3 large whole eggs + 3 large egg whites at room temperature
• 1 cup finely ground almond flour
• 1 teaspoon vanilla paste
• 1/4 teaspoon coarse salt
• 3/4 cup sugar
• 0.5 cups premium flour
• 2 tablespoons unsalted butter, slightly melted and cooled

Coffee impregnation

• 3 tablespoons espresso powder
• 2 tablespoons of sugar

Chocolate ganache

• 0.5 cups heavy cream
• 1 cup 75% dark chocolate (about 170 g), chopped

Coffee French buttercream

• 4 large egg yolks at room temperature
• 1 cup of sugar
• 190 g unsalted butter, diced, at room temperature
• 1 teaspoon vanilla paste
• 0.5 tsp coarse salt
• 1 tbsp espresso powder

Chocolate glaze

• 1 cup 75% dark chocolate (about 170 g), chopped
• 1 tbsp. refined coconut oil
• Special equipment: caramel or deep-fry thermometer, stand mixer with whisk attachment

Preparation:

1. Almond sponge cake: Preheat oven to 190°C and line a baking sheet with parchment paper.
   
   In a large bowl, whisk together 3 whole eggs, almond flour, vanilla extract, salt, and 1/2 cup sugar until smooth; set aside. Meanwhile, in the bowl of a stand mixer fitted with the whisk attachment, beat 3 egg whites with the remaining 1/4 cup sugar on medium-high speed until stiff, glossy peaks form, 2 to 4 minutes.
2. Using a clean spatula, carefully fold half the egg white mixture into the almond flour batter, being careful not to let the egg whites fall. Add the remaining beaten egg whites and fold in. Sift the flour through a fine-mesh sieve over the batter and fold in gently. Finally, add the melted butter, pouring it around the edges of the bowl, then fold until smooth.
3. Pour the batter onto the prepared rimmed baking sheet and smooth it out with a spatula. Bake until the cake is puffed, cooked through, and springs back when lightly pressed, 12–14 minutes. Let it cool on the baking sheet for 5 minutes, then run a knife around the edges of the pan to loosen the edges. Invert onto a wire rack, carefully peel off the parchment, and let cool completely. The cake should be thin (about 0.5 cm).
4. Coffee impregnationWhile the cake is cooling, combine 1/2 cup warm water, espresso powder, and sugar in a liquid measuring cup until the sugar is completely dissolved. Set aside.
   
   Chocolate ganacheHeat the cream in a small saucepan over medium heat until just simmering, about 2 minutes.
   
   Place the chocolate in a medium bowl and pour the hot cream over it. Let it sit until the chocolate softens, about 2 minutes, then stir with a spatula until completely smooth. Let the ganache cool until it thickens but is still easy to spread.
5. Coffee French buttercreamBeat the egg yolks on medium-high speed until pale yellow and thick, about 5 minutes.
   
   Meanwhile, in a medium saucepan, combine the sugar and 1/4 cup water. Attach a thermometer to the side of the pan and cook over medium heat until the syrup reaches the soft-ball stage (115°C), swirling the pan occasionally, for 4–5 minutes.
6. Reduce mixer speed to medium and slowly pour in the hot syrup, working it between the sides of the bowl and the whisk. Once all the syrup has been added, increase mixer speed to medium-high and continue beating until the bottom of the bowl and the mixture have cooled, about 10 minutes. The mixture should be thick, but not peak-like at this point.
7. Continuing to beat at medium-high speed, add the diced butter, a few pieces at a time, and beat until stiff peaks form, 1–2 minutes. The cream may seem to thin slightly as you add the butter, but continue beating, and it will thicken. Stir in the vanilla extract and salt. Dissolve the espresso powder in 1 tablespoon of water, then fold it into the buttercream. Beat until smooth, about 1 minute. Set aside at room temperature until ready to assemble.
8. Assembly: Cut the almond sponge cake crosswise into three equal parts (each approximately 15x32 cm).
   
   Place one cake layer on a long serving platter. Spread a third of the coffee icing on top. Spread half of the ganache in an even layer, making sure it reaches the edges. Spread about 3/4 cup of buttercream over the ganache, also in an even layer. Place another cake layer on top and pour half of the remaining icing on top. Frost the cake with the remaining ganache and 3/4 cup of buttercream. Place the third and final cake layer on top and frost with the remaining icing. Frost the top and sides of the cake with the remaining buttercream, making sure the layer is as even as possible (this will ensure the icing sits flat). Refrigerate until the cake is completely set, at least 1 hour and up to overnight.
9. Chocolate glaze: Pour 0.5 cups of water into a small saucepan and bring to a boil over medium heat.
   
   Place the chopped chocolate and coconut oil in a medium heatproof bowl, then set the bowl over simmering water (the bottom of the bowl should not touch the water). Stir the chocolate with a silicone spatula until smooth, 2–3 minutes. Remove from heat and pour into a large liquid measuring cup. Let the glaze cool for about 5 minutes.
10. Remove the cake from the refrigerator. Working quickly, coat the cake with an even, thin layer of icing; it will set quickly as the cake cools. If necessary, smooth the icing quickly with a spatula. Refrigerate until set, about 10 minutes.
11. Before serving, run a serrated knife under hot water for 30 seconds, then dry with a clean kitchen towel (this will ensure a neat cut). Slice the cake crosswise into 2-cm-thick slices, moving slowly to prevent the chocolate glaze from cracking. Serve immediately or refrigerate the slices in a tightly sealed container for up to 3 days.