Daring Bakers Challenge: L'Opera Cake

Having been gone on vacation to California during the reveal date of this challenge, I had requested if I was able to post my DB challenge post at a later date. And voila! Here it is... finally, my first DB post... a little late, but worth the wait I must say :P

A Taste of Light: Opéra Cake
This recipe is based on Opéra Cake recipes in Dorie Greenspan’s Paris Sweets and Tish Boyle and Timothy Moriarty’s Chocolate Passion.

For the 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) ground blanched almonds (Note: since my sister is allergic to nutmeat, I chose to ground up some blanched pine nuts in my coffee grinder, with a little bit of flour, and it worked out very well.)
- 2 cups icing sugar, sifted
- 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.In the bowl of a stand mixer fitted with the whisk attachment (or using a handheld mixer), beat the egg whites until they form soft peaks. Add the granulated sugar and beat until the peaks are stiff and glossy. If you do not have another mixer bowl, gently scrape the meringue into another bowl and set aside.

5. If you only have one bowl, wash it after removing the egg whites or if you have a second bowl, use that one. Attach the paddle attachment to the stand mixer (or using a handheld mixer again) and beat the almonds, icing sugar and eggs on medium speed until light and voluminous, about 3 minutes.

6.Add the flour and beat on low speed until the flour is just combined (be very careful not to overmix here!!!).

7.Using a rubber spatula, gently fold the meringue into the almond mixture and then fold in the melted butter. Divide the batter between the pans and spread it evenly to cover the entire surface of each pan.

8.Bake the cake layers until they are lightly browned and just springy to the touch. This could take anywhere from 5 to 9 minutes depending on your oven. Place one jelly-roll pan in the middle of the oven and the second jelly-roll pan in the bottom third of the oven.

9.Put the pans on a heatproof counter and run a sharp knife along the edges of the cake to loosen it from the pan. Cover each with a sheet of parchment or wax paper, turn the pans over, and unmold.

10. Carefully peel away the parchment, then turn the parchment over and use it to cover the cakes. Let the cakes cool to room temperature.

For the Syrup
Note: The syrup can be made up to 1 week in advance and kept covered in the refrigerator.)

Ingredients:
- ½ cup (125 grams) water
- ⅓ cup (65 grams) granulated sugar
- 1 to 2 tbsp. of honey (you may also use vanilla extract, almond extract, cognac, limoncello, coconut cream, etc.)

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.

For the Honey Buttercream

(Note: The buttercream can be made up to 1 month in advance and packed in an airtight container. If made way in advance, you can freeze the buttercream. Alternatively you can refrigerate it for up to 4 days after making it. To use the buttercream simply bring it to room temperature and then beat it briefly to restore its consistency.)

Ingredients:
- 1 cup butter, room temperature
- ¼ cup honey
- 3 large egg yolk
-1 tbsp vanilla (optional)

1. In a small saucepan, heat honey to 225◦F (107◦C) and slowly add in the egg yolks; whisking constantly.

2. Raise the speed to medium-high and continue beating until the eggs are thick and satiny and the mixture is cool to the touch (5 minutes or so).

3.When mixture cools, add in beaten butter.

4. With the mixer on medium speed, begin adding in two-tablespoon chunks. When all the butter has been incorporated, raise the mixer speed to high and beat until the buttercream is thick and shiny.

5. At this point add in vanilla and beat for an additional minute or so.

6. 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).

For the White Chocolate Ganache/Mousse
(Note: The mousse can be made ahead and refrigerated until you’re ready to use it.)

Ingredients:
- 7 ounces white chocolate
- 1 cup plus 3 tbsp heavy cream (35% cream)
- 1 tbsp liquer of your choice (Bailey’s, Amaretto, etc.)

1.Melt white chocolate and the 3 tbsp heavy cream in a small saucepan.

2.Stir to ensure that it’s smooth and that the chocolate is melted. Add the tbsp 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 whipped cream into cooled chocolate to form a mousse.

5.If it’s too thin, refrigerate it for a bit until it’s spreadable.

6.If you’re not going to use it right away, refrigerate until you’re ready to use.

For 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 the Opéra Cake

(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.

Steps:

1. Place one square of cake on the baking sheet and moisten it gently with the flavoured syrup.

2. Spread about three-quarters of the buttercream over this layer.

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

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

5. Prepare the ganache/mousse (if you haven’t already) and then spread it on the top of the last layer of the joconde. Refrigerate for at least two to three hours to give the ganache/mousse the opportunity to firm up.

6. 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.

7. Serve the cake slightly chilled; recipe yields approximately 20 servings.

This experience has been a challenging one, but an adventure none-the-less. I really enjoyed attempting a new level of creativity in my baking skills. I can hardly wait until next month's challenge. Yeay for Daring Bakers! I have now joined their ranks...