Opera Cake

I promised that I would share some desserts that I made for the holiday season and this was the main dessert I served for Christmas Eve supper.  I've been wanting to make an Opera cake for the longest time and I'm pretty happy with the results.  I'm a huge fan of the combination of chocolate, espresso, and almonds.  I also know that I'm not alone, it's a generally a crowd pleasing combination, such as my Chocolate Espresso Dacquoise.  Actually, the cake gets assembled in a similar way but I have a tutorial below.  I really enjoyed making the cake and I loved how it had many steps involved but none of them were too complicated.

In the fear that I would not have enough cake (scary thought), I made an 8x8 inch cake rather than 7x7 inch, in which I ended up making 1.5 of the almond sponge cake.  I used my hotel baking sheet which was 16.5x11.5 inches and for the ganache, I used 8oz of semi-sweet chocolate and 8 tablespoons of butter.  Since this was a multi-step cake, I chose to make it in advance but I recommend trimming the edges the day you plan on serving the cake.  The cake does get heavily doused with the syrup so there shouldn't be any fears of having it dry out.  To serve the cake, slice it into rectangles with a sharp serrated knife and serve a room temperature.  In the end, I had plenty of leftover cake and I was happily enjoying my leftovers the following day!  This cake is delicious for any occasion!

Whole eggs got beaten until it tripled in volume. The almond flour and confectioners sugar got incorporated with the egg mixture.

The cake flour was then sifted over the egg mixture.

I folded everything gently with a spatula.

Meanwhile in another mixing bowl, the egg whites were beaten until foamy.  I added cream of tartar and salt then increased the speed of the mixer to high.

The egg whites were whipped until stiff peaks.

A third of the whites were put into the almond batter and folded to lightened the batter.

The remaining egg whites were folded into the batter.

I spread the batter evenly with the help of an offset spatula.

The cake was baked until golden and was set to cool.

I sliced the cake into 2 squares and two rectangles to form the 3 layers of cake.

This was the coffee buttercream right after the hot syrup was added to the egg yolks.

Here is the coffee buttercream once it was ready, it was nice and light.

The coffee syrup was easy to assemble.

I melted the chocolate and butter over a double boiler to make a smooth glaze.

I assembled the cake by starting off with a square piece of cake.

I brushed it with the syrup.

Then I spread over half of the coffee buttercream.

I placed the smaller rectangle pieces to form the middle layer.

Followed by brushing it with the coffee syrup.

Then half of the chocolate glaze got spread over the cake.

The last piece of cake was placed.

Followed by the remaining coffee buttercream.

The final touch was putting the chocolate glaze over the cake.

The cake was chilled in the fridge and the edges were trimmed before serving.

The clean edges really show off the different layers of the cake.

Opera Cake
Serves 6 to 8

For Almond Sponge Cake
3 tablespoons cake flour
2 large whole eggs, room temperature
2 large egg whites, room temperature
1 cup almond flour
1/2 cup confectioner's sugar, sifted after measuring
1/8 teaspoon cream of tartar
1/8 teaspoons salt
1 tablespoons granulated sugar
2 tablespoons unsalted butter, melted and cooled

Put the oven rack in the middle position, preheat to 425 F.  Butter a 15-by 10 inch shallow baking pan, then line with the bottom with parchment paper, butter the paper as well.  Dust pan with cake flour, knocking out excess.  Set aside.

Beat the whole eggs until triple in volume, about 2-3 minutes.  Reduce the speed to low, add almond flour and confectioners sugar, mix to combine.  Sift the cake flour into the batter and gently fold.

In another bowl, beat the egg whites until foamy.  Add cream of tartar and salt, beat to a soft peak, add granulated sugar, increase the speed to high, continue to beat until stiff peak.

Fold 1/3 of the whites into almond batter to lighten it, then fold the remaining whites gently.  Fold in melted butter, spread the batter evenly into the baking pan.

Bake 10 minutes until golden pale.  Cool in a pan for 10 minutes, then loosen the edge with spatula.  Transfer the cake with its parchment paper to a cutting board.

To make a three layer cake, here's how to cut the cake: first, cut the cake into half crosswise.  Second, cut off 3 1/4 inch wide strip from the bottom of each half so you have a total of 2 roughly 7 inch squares and 2 roughly 3 by 7 inch rectangles.  Put the 2 rectangles to make the square middle cake layer.

For Coffee Syrup
1 teaspoon instant-espresso powder
1/2 cup + 1 tablespoon water
1/2 cup granulated sugar
1/4 cup amaretto liquor

Dissolve espresso and 1 tablespoon of water.  Set aside.

Bring sugar and remaining water to a boil, stirring until sugar melted, reduce heat and simmer without stirring until it becomes syrupy.  Remove from heat, stir in amaretto and espresso mixture.

For Coffee Buttercream
2 teaspoons instant-espresso powder
1/4 cup + 1 tablespoon water
6 tablespoons granulated sugar
2 large egg yolks
1 stick unsalted butter, cut into 1/2 inch cubes and softened

Dissolve espresso powder with 1 tablespoon water.  Set aside.
Bring sugar and remaining 1/4 cup water to a boil.  Stir until sugar dissolves, then continue to boil without stirring until syrupy and reaches 238F.

While the syrup is boiling, beat the egg yolks at medium speed for 1 minute, add hot syrup in a slow stream, add coffee mixture, continue to beat until cool about 3-5 minutes.  Beat in butter a piece at a time.  Continue to beat until thickened and smooth.

For Chocolate Glaze:
6 tablespoons unsalted butter
7 oz semisweet chocolate, coarsely chopped

Melt the chocolate and butter in a double boiler over barely simmering water.  Stir until smooth.  Remove from the heat, cool at room temperature.

Assemble Cake

Place 1 sheet of cake on a plate, brush generously with coffee syrup.  Spread buttercream evenly.  Place the rectangular cakes side by side on top of the buttercream, brush with coffee syrup, spread half of the chocolate glaze.  Place the last layer of cake, brush with coffee syrup, spread the remaining buttercream evenly.  Chill the cake until firm, about 30 minutes.

Reheat the glaze until warm to the touch about 88F.  Pour the glaze over chilled cake and spread evenly.  Chill the cake until the glaze is set.  Trim the edges with a sharp serrated knife.

Source: slightly adapted from Elra's Baking and from Gourmet Magazine, September 2004