Daring Bakers May Challenge: Opera Cake

When I read what the Daring Bakers challenge was for this month was, I mentally said "yeah, right" and thought I'd be sitting this one out, leaving Aamena to do her creative work. But she's tied up in final exams so it fell to me.
The challenge was chosen by lovely hosts Ivonne and Lis, along with co-hosts Fran of Apples Peaches Pumpkin Pie  and Shea of Whiskful.



An Opera Cake consists of the joconde - an almond sponge; the syrup, to wet the cake, buttercream, ganache (optional) and a final glaze. I'm not good at complicated things, so I read the recipe about five times, but I only made it today because I was away for a week visiting in-laws. I only got back yesterday, and I was too tired to even think about making even the base. So I had to do everything today. A recipe for disaster, or at least some last minute problems. Like the store being out of blanched almond meal, so you end up using unblanched. And not finding the right size jelly roll tins and not having any two of the same size at home.




A Taste of Light: Opera Cake

Adapted from Dorie Greenspan’s Paris Sweets and Tish Boyle and Timothy Moriarty’s Chocolate Passion.

Joconde
(Note: The joconde can be made up to 1 day in advance and kept wrapped at room temperate)
Ingredients:
6 large egg whites, at room temperature
2 tbsp. (30 grams) granulated sugar
2 cups (225 grams) blanched almond meal
2 cups icing sugar, sifted (220 gm)
6 large eggs
½ cup (70 grams) all-purpose flour
3 tbsp. (1½ ounces; 45 grams) unsalted butter, melted and cooled

1. Divide the oven into thirds by positioning a rack in the upper third of the oven and the lower third of the oven.
2. Preheat the oven to 425◦F. (220◦C).
3. Line two 12½ x 15½- inch (31 x 39-cm) jelly-roll pans with parchment paper and brush with melted butter.
4. Beat the egg whites until they form soft peaks. Add the granulated sugar and beat until stiff and glossy. Set aside.
5. In another bowl, beat the almonds, icing sugar and eggs on medium speed until light and voluminous, about 3 minutes.
6. Add the flour and beat until just combined (do not overmix).
7. Using a rubber spatula, fold the egg white into the almond mixture and then fold in the melted butter. Divide the batter between the pans and spread it evenly.
8. Bake until light brown and springy to the touch, 5 to 9 minutes.
9. Run a sharp knife along the edges of the cakes to loosen. Cover each with a sheet of parchment or wax paper, turn the pans over, and unmold.
10. Peel off the parchment, then turn the paper over and use it to cover the cakes. Let the cakes cool to room temperature.

Syrup
Ingredients:
½ cup (125 grams) water
⅓ cup (65 grams) granulated sugar
1 to 2 tbsp. of a flavoring of your choice (I used lemon zest)

1. Stir all the syrup ingredients together in the saucepan and bring to a boil.
2. Remove from the heat and let cool to room temperature.

Buttercream
Ingredients:
1 cup (100 grams) granulated sugar
¼ cup (60 grams) water
seeds of one vanilla bean or 1 tbsp. pure vanilla extract (I used a vanilla bean paste I found at Surfas)
1 large egg
1 large egg yolk
1¾ sticks (7 ounces; 200 grams) unsalted butter, at room temperature
Flavoring of your choice (I used lemon zest)

1. Combine the sugar, water and vanilla in a small saucepan and warm over medium heat just until the sugar dissolves.
2. Continue to cook, without stirring, until the syrup reaches 225◦F (107◦C) Remove the syrup from the heat.
3. While the syrup is heating, whisk the egg and egg yolk at high speed until pale and foamy.
4. Reduce the mixer speed to low speed and begin very slowly pouring the syrup down the side of the bowl being very careful not to splatter the syrup into the path of the whisk attachment.
5. Raise the speed to medium-high and continue beating until the eggs are thick and satiny and the mixture is cool to the touch (about 5 minutes or so).
6. In a bowl, mash the softened butter in a bowl with a spatula. 
7. Add the butter in 2-tablespoon chunks. When all the butter has been added, raise the mixer speed to high and beat until the buttercream is thick and shiny.
8. Add flavouring and beat for an additional minute or so.
9. Refrigerate the buttercream, stirring it often, until it’s set enough (firm enough) to spread when topped with a layer of cake (about 20 minutes).

White chocolate ganache/mousse (this step is optional – I skipped it)
Ingredients:
7 ounces white chocolate
1 cup plus 3 tbsp. heavy cream (35% cream)
1 tbsp. liqueur of your choice (Bailey’s, Amaretto, etc.)

1. Melt the white chocolate and the 3 tbsp. of heavy cream in a small saucepan.
2. Stir and add the tablespoon of liqueur to the chocolate and stir. Set aside to cool completely.
3. In the bowl of a stand mixer, whip the remaining 1 cup of heavy cream until soft peaks form.
4. Gently fold the whipped cream into the cooled chocolate to form a mousse.
5. If it’s too thin, refrigerate it for a bit until it’s spreadable and you're ready to use it.
6. If you’re not going to use it right away, refrigerate until you’re ready to use.

The glaze
(Note: It’s best to make the glaze right when you’re ready to finish the cake.)
Ingredients:
14 ounces white chocolate, coarsely chopped
½ cup heavy cream (35% cream)

1.Melt the white chocolate with the heavy cream. Whisk the mixture gently until smooth.
2.Let cool for 10 minutes and then pour over the chilled cake. Using a long metal cake spatula, smooth out into an even layer.
3.Place the cake into the refrigerator for 30 minutes to set.

Assembling
(Note: The finished cake should be served slightly chilled. It can be kept in the refrigerator for up to 1 day).

Line a baking sheet with parchment or wax paper.

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.
Obviously, I didn't need to to do this, since I used 9-inch round tins.
Step A (if using buttercream only and not making the ganache/mousse):

Moisten a layer of the cake with the flavoured syrup.

Spread about one-third of the buttercream over this layer.

Top with the two rectangular pieces of cake, placing them side by side to form a square, or whatever shape. Moisten these pieces with the flavoured syrup.

Spread another third of the buttercream on the cake and then top with the third square of joconde. Use the remaining syrup to wet the joconde. Spread the remaining buttercream on top of the final layer of joconde and then refrigerate until very firm (at least half an hour).

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.

Serve the cake slightly chilled. This recipe will yield approximately 20 servings.


As is clear from the long instructions, this is was quite a challenge. But truthfully each step went quite smoothly. My only problem was was that the buttercream was a bit runny, after I put on the glaze, the top layer of buttercream started to slip a bit. And the layers of joconde are a bit thick, I wish i had had a fourth 9 inch tin to make thinner layers.