Wednesday, May 28, 2008

daring bakers - opera cake

if you've ever been to paris, you'll know that the opera garnier is a pretty funky place (with some great cafes near by). this month's daring baker's challenge was the opera cake. i hazard to guess that the fine inventor of this cake, whose name escapes me, thought it looked a bit like the baroque-esque features of this amazing building. if you'd like to make one, this is the way you would go about it:

An opera cake is layers of joconde (basically an almond meal and meringue sponge) soaked in surup and layered with lots of dairy fat. so there are a few pieces you'll need to get together:

the joconde

6 large egg whites, at room temperature
2 tbsp. (30 grams) caster sugar
2 cups (225 grams) ground blanched almonds
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

preheat the oven to 425◦F. (220◦C),and divide the oven space into third

line two 12½ x 15½- inch (31 x 39-cm) swiss-roll pans with parchment paper and brush with melted butter.

beat the egg whites until they form soft peaks. add the 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.

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.

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

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.

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 swiss roll pan in the middle of the oven and the second in the bottom third of the oven. it may be necessary to swap the pans half way through the cooking process to ensure they cook evenly.

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.

carefully peel away the parchment, then turn the parchment over and use it to cover the cakes. let the cakes cool to room temperature.

the syrup
½ cup (125 grams) water
⅓ cup (65 grams) granulated sugar
1 to 2 tbsp. of the flavouring of your choice (i used honey)

stir all the syrup ingredients together in the saucepan and bring to a boil.

remove from the heat and let cool to room temperature.

the buttercream
1 cup (100 grams) caster sugar
¼ cup (60 grams) water
seeds of one vanilla bean/vanilla extract/essence etc
1 large egg
1 large egg yolk
1¾ sticks (7 ounces; 200 grams) unsalted butter, at room temperature
flavouring of your choice (i used a couple of mashed up bananas)

combine the sugar, water and vanilla bean seeds or extract in a small saucepan and warm over medium heat just until the sugar dissolves.

continue to cook, without stirring, until the syrup reaches 225◦F (107◦C) on a candy or instant-read thermometer. once it reaches that temperature, remove the syrup from the heat.

while the syrup is heating, begin whisking the egg and egg yolk at high speed in the bowl of your mixer using the whisk attachment. whisk them until they are pale and foamy.

when the sugar syrup reaches the correct temperature and you remove it from the heat, reduce the mixer speed to low speed and begin slowly (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. Some of the syrup will spin onto the sides of the bowl but don’t worry about this and don’t try to stir it into the mixture as it will harden!

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).

while the egg mixture is beating, place the softened butter in a bowl and mash it with a spatula until you have a soft creamy mass.

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. then add the banana

refrigerate the buttercream, stirring it often, until it’s set enough to spread when topped with a layer of cake (about 20 minutes).

white chocolate ganache/mousse
7 ounces (200g) white chocolate
1 cup plus 3 tbsp. heavy cream (35% cream)
1 tbsp. liqueur of your choice (i sued frangelico)

Melt the white chocolate and the 3 tbsp. of heavy cream in a small saucepan. stir to ensure that it’s smooth and that the chocolate is melted. add the tablespoon of liqueur to the chocolate and stir. set aside to cool completely.

in a bowl of a stand mixer, whip the remaining 1 cup of heavy cream until soft peaks form. gently fold the whipped cream into the cooled chocolate to form a mousse.

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

the glaze (make just as you're getting the whole thing together - see below)

14 ounces (400g) white chocolate, coarsely chopped
½ cup heavy cream (35% cream)

melt the white chocolate with the heavy cream. whisk the mixture gently until smooth.

let cool for 10 minutes and then pour over the chilled cake. using a long metal cake spatula, smooth out into an even layer. place the cake into the refrigerator for 30 minutes to set.

getting it all together
ok, this is the tricky bit. to start off with you need three layers of cake. 'but hey crazy lady' i hear you say, 'i only have two cakes'.

well yes, i know. so cut a third off the end off each cake. you now have two 2/3 cakes, and two 1/3 cakes. so you put the two 1/3s together and now you have 3 2/3 of a cake. hope that makes sense!

so you get a full piece of cake, drizzle it with a third of the syrup and then using a spatula spread out half of the butter cream.

now take the two ends that you cut off the cakes and place them together to make the new layer. again, drizzle with syrup and smooth over the butter cream.

put the last layer of cake on and drizzle with the last of the syrup. but this time spread the cream mousse over the top. make sure it's fairly even on the top and bung it in the fridge for several hours to get it really cold.

this is the time to start making the glaze, as per the instructions above. spread it all out over the cooled cake and smooth it off with your spatula. get it back in the fridge to set. once it's ready to serve just trim off the edges to expose the layers. these cut off bits make a really good alternative to beer when you come home from a late meeting all stressed and snipey.

et voila! mon gateau au opera!

overall mine was a great success. normally opera cake is make with dark chocolate, but the DB lasses made this one white as a celebration of spring. of course in australia it's lovely and crisp and frosty and autumn. i love autumn, so i'm quite happy to celebrate that instead.

the only problem with my execution of this was that the banana made the butter cream a bit soggy, and as i only have one pan i had to cook the layers of the jaconde separately, so they were a bit uneven when it came to putting it together. it was also a bit fiddly, but i'm sure the next time i make it, it will all be a bit more straight forward - although i did wash a gazzilion bowls!

this is certainly a special occasion cake, but worth a shot. cereal. i didn't actually get to eat any of it, because i took it to work and my 'friends' ate it all before i got a piece. the reports were good. i guess that's it settled, i will have to make it again. tee hee.


marye said...

I love your image! The leaves are great. Autumn is my favorite season.

Your cake is lovely!

Christine said...

Love your pic! Great job!

Marilla said...

wow your cake came out great!

mine came out a bit lopsided and slidy, but tasted delicious and I guess thats what really counts!

Shari said...

Love the leaves around your cake!
Shari@Whisk: a food blog

Claire said...

I love autumn, too...except, in MS we have about 3 days of it (spring as well...all else is winter and summer!). Looks great!

Kitty said...

thanks ladies for all your kind words. i like the picture too (although i must admit i nicked the idea from Nigella Lawson).

i was really amazed at how easily it all came together after my initial shock at seeing the recipe. i'm off to check out all of yours now!

Ami said...

Beautiful autumn cake! It's not even summer yet, and I'm waiting for fall....

Anonymous said...

mmmmm, banana, love it! - I'm really loving the light coloured cakes, they're just beautiful, so ethereal :)

Rebecca said...

Gorgeous photo! Wish it were autumn here instead of 90 degrees!

Dolores said...

Glorious gateaux l'opera. I love the banana essence and the autumnal image. Great job!

Sheltie Girl said...

You did a beautiful job on your cake. Lovely picture!

Natalie @ Gluten A Go Go