Gâteau L'Opéra

Gâteau L'Opéra.  The cake said to resemble and celebrate the Paris Opera House.  The elaborate layers of almond sponge soaked in espresso, coffee buttercream and chocolate ganache reminiscing the layers of baroque architecture.  Romantic, huh?  Decadently delicous, too.  (With all that dark chocolate ganache and buttercream, how could it not be?!)

 

Gâteau L'Opéra
makes 1 4x9" cake

For the almond sponge cake
50g almond powder
60g powdered sugar
15g all-purpose flour
2 whole eggs
1 egg white
10g butter, melted

For the chocolate ganache
150g dark chocolate, chopped
70g whole milk
70g heavy cream

For the coffee syrup
25g sugar
100ml hot water
3g instant espresso powder

For the coffee buttercream
100g sugar
20ml water
3g corn syrup
1 whole egg
1 egg white
1g salt
5g instant espresso powder
230g butter, softened at room temperature

Begin with the almond sponge cake.  Preheat oven to 200ºC.
In a medium mixing bowl, beat eggs and egg white on high speed with a hand mixer for 1 minute.  Add powdered sugar, then beat 1 more minute until combined.

Combine flour and almond powder.  Gently fold into egg mixture in 3 additions, making sure dry ingredients are well incorporated after each addition.  Stir in melted butter.  Line a  13"x9" baking sheet with parchment paper.  Pour batter onto prepared baking sheet, spreading evenly with an offset spatula.

Bake for 10 minutes until golden on top.  Let cool on wire rack.

Next, prepare the chocolate ganache.  Combine milk and cream in a small saucepan.  Bring to a boil and remove from heat immediately.

Place chocolate in a medium bowl and pour hot milk mixture over.  Let sit for one minute.

Gently whisk until ganache is smooth and shiny.  Set aside for later use.

Now for the coffee buttercream.  In a small saucepan, combine water, sugar and corn syrup.  Bring to a boil, then remove from heat immediately.

In a mixing bowl with a hand mixer, beat together salt, egg and egg white on high speed for 1 minute.

Decrease speed to low.  While beating, slowly stream in hot sugar mixture.  Gradually increase speed to high and continue beating until mixture cools 40ºC, about 3 more minutes.

On low speed, continue beating while adding butter 1 tablespoon at a time.  Make sure butter is fully incorporated after each addition.

Add instant espresso powder and beat for 1 more minute.

Set coffee buttercream aside for later use.

Lastly, the coffee syrup.  Combine espresso powder, sugar and hot water in a small bowl.  Whisk until smooth.

To assemble.

Cut cooled almond sponge cake into three equal parts (approximately 4"x9" pieces).

On a small baking tray lined with parchment, place 1 piece of sponge cake on top.  With a pastry brush, generously coat the cake with coffee syrup.

With an offset spatula, spread 1/3 of the coffee buttercream on top of the cake.  Smooth evenly with the offset spatula to ensure an even surface.  Refrigerate for 10 minutes.

Remove cake from fridge.  Spread 1/3 of the chocolate ganache on top of the buttercream.  Smooth evenly with an offset spatula.

Top with second piece of sponge cake.  Repeat layering steps 2 more times, ending with a chocolate layer.

Decorate the top layer with nuts or chocolate pieces as desired.



Refrigerate for at least 30 mintues.  With a sharp chef's knife, trim the edges on all four sides.

Remove from fridge 10 minutes before serving for optimal texture in the buttercream and ganache!