Opera Cake

What is an opera cake?

An opera cake (Opéra gâteau) is a French cake. It has intricate layers and is flavored with coffee and chocolate, similar to an Italian tiramisu.

fun fact: the music animation doesn't just have random notes!
the notes come from the overture of a famous opera. can you guess which one?

The Opera Cake in History

As you can see from the many layers in this cake, there's a lot going on here. According to my research (aka Wikipedia and some random websites online), there's also a lot going on with who invented the opera cake. While there seems to be agreement that the French patisserie Dalloyau popularized the cake, there seems to be a few ideas regarding the origin of the cake.

Dalloyau states that Cyrique Gavillon invented the dessert in 1955. The name of the opera cake comes from its appearance as its layers as the cake reminded his wife of the Paris Opera House, Palais Garnier. 

However, there are also other online sources that state that the opera cake premiered as the Clichy, named after Louis Clichy, at the 1903 Exposition Culinaire in Paris and was simply popularized by Dalloyau. 

Opera Cake Anatomy

While the historical origin of the opera cake seems to be complicated, the makeup of the cake is as well, so here's a little breakdown of the opera cake anatomy. I can't speak for the traditional opera cake, but this is the version that I made. 

chocolate croustillant

Chocolate croustillant is a fancy French way to describe crunchy chocolate stuff. It's essentially made of super thin crispy lacy crepes covered in chocolate. 

joconde sponge

Another fancy sounding phrase, the joconde sponge is essentially an almond sponge cake. 

coffee syrup

Kind of like a tiramisu, the cake is brushed with a coffee syrup. This allows the coffee to soak into the cake and give it the coffee flavor.

coffee buttercream

The coffee buttercream has a subtle coffee flavor to it and a lightness to it. Although it's coffee flavored, it has a yellow tinge to it. This is because it is a French buttercream, which means that it's made from egg yolks, a sugar syrup, and butter. The egg yolks give it the yellowish color.

chocolate ganache

Deliciously rich chocolate. 

Opera Cake

The opera cake is far from simple — but its elegance and coffee-chocolate flavor combination is worth the effort.

Yield: 14-16 pieces

Ingredients:

For the almond cake
6 large egg whites, room temperature
2 tablespoons granulated sugar
2 cups ground blanched almonds or almond flour
2 1/4 cups confectioners' sugar, sifted
6 large eggs
1/2 cup all-purpose flour
3 tablespoons butter, melted and cooled

For the chocolate croustillant
1/3 cup butter
1/3 cup granulated sugar
1 egg white
1/3 cup flour
2 tablespoons water
4 oz semisweet chocolate

For the coffee syrup/soak
2/3 cup water
1/2 cup sugar
3 tsp instant coffee

For the coffee buttercream
5 egg yolks, room temperature
3/4 cup sugar
3 tbsp water
2 tsp instant coffee
1 1/4 cup butter, softened

For the chocolate ganache
4 oz semisweet chocolate, chopped
1/2 cup heavy whipping cream

For the chocolate glaze
7 oz semisweet chocolate, chopped
2 tbs canola oil

Instructions:

1. Preheat the oven to 425 F. Line two 15-inch by 12-inch pans with parchment paper and brush the surface of the paper with butter. Set aside.
2. Make the almond cake: beat the egg whites on high until they become foamy and start to expand. Sprinkle in the sugar, one teaspoon at a time, until all of it is incorporated into the egg whites. Continue beating the meringue until it is glossy and holds stiff peaks.
3. In a separate bowl, beat the ground almonds, confectioners' sugar, and whole eggs on medium just until the mixture becomes light and foamy.
4. Stir the all-purpose flour into the almond batter.
5. Gently stir 1/4 of the almond batter into the whipped egg whites. Fold the remainder of the almond batter and the melted, cooled butter into the egg whites.
6. Divide the sponge cake batter between the two prepared pans and bake the cakes for 5 minutes, until the surfaces spring back from a light touch.
7. Let cool and then cut into two 10 inch by 10 inch squares. There should be two 5 inch by 10 inch rectangles left. These laid side by side will make up the third cake square. 
8. Make the chocolate croustillant: Preheat the oven to 400 ºF (200 ºC) .
9. Melt the butter completely in a mixing bowl. Add sugar to hot butter and mix so sugar is completely dissolved.
10. Whisk in egg white then add flour when mixture is cool. 
11. Slowly add the water bit by bit and mix well until it resembles a crepe batter. You don't have to use all the water, just use as much as you need. 
12. Spread the batter evenly on a baking tray lined with parchment paper. It should be very very thin and you should be able to vaguely see through the batter. 
13. Bake for 5 to 8 minutes or until brown. Watch carefully, as it can burn very quickly. 
14. Remove from oven and let cool. Crush into small pieces. 
15. Melt the chocolate and stir in the crushed crisps.
16. Spread the chocolate croustillant on top of one of the squares of cake and refrigerate to set. 
17. Make the coffee syrup/soak: Bring water, sugar, and instant coffee to a boil in a small saucepan. Set aside to cool.
18. Make the coffee buttercream: Mix the egg yolks in a heatproof bowl. 
19. Combine sugar, water, and instant coffee in a small saucepan. When mixture reaches 240 degrees Fahrenheit (or 115 degrees Celsius) gradually pour over the egg yolks while mixing. Mix until cool.
20. Mix on low and add softened butter until incorporated. Increase speed to high and mix until fluffy.
21. Make the chocolate ganache: Bring the heavy cream to a boil and then pour hot cream over the chopped chocolate. Let chocolate sit in cream for about 30 seconds then mix until smooth.
22. Assemble the cake: Place the cake layer with the chocolate croustillant down, with the chocolate croustillant facing down. 
23. Brush the cake layer generously with the coffee soak. 
24. Spread half of the coffee buttercream on the cake layer.
25. Place the two 5 inch by 10 inch rectangles side by side to create a 10 inch by 10 inch cake square. 
26. Brush the cake layer generously with the coffee soak.
27. Spread the chocolate ganache on the cake layer.
28. Place the final cake layer.
29. Brush cake layer generously with the coffee soak.
30. Spread the remaining coffee buttercream.
31. Make the chocolate glaze: Using a double boiler method, melt the chopped chocolate. When melted, stir in the canola oil. Let cool to room temperature. 
32. Pour cooled chocolate glaze over cake and place cake in refrigerator to set. 
33. Once set, use a hot knife (dip in hot water and wipe dry) to cut off the edges of the cake to reveal the layers. 
34. (Optional) cut into rectangles with a hot knife. After cutting of the edges, the cake should be around 9 inches by 9 inches. Cut two rows of 4 inch by 1.5 inch rectangles (12 pieces) and then cut the remaining cake into 4.5 inch by 1 inch rectangles. View cutting guide below for reference.