May « 2011 « Pigs in Blankets

22May/1132

Chocolate Opera Cake

An Opera cake is a layered cake, usually made with chocolate and coffee. However, I hate coffee, so my cake is a chocolate overdose. It is pretty time consuming and probably not the best to have if you are on a diet or watching what you eat. It is, however, a crowd pleaser and pretty damn delicious if I may say so.

Joconde

Ingredients

175 g egg whites
125 g sugar
275 g beaten eggs
205 g powdered almonds
115 g confectioner's sugar
60 g flour
30 g butter

Procedure

This recipe yields three joconde sponge cake sheets. If you have a professional oven in which you can bake stuff on several trays simultaneously (e.g. you can bake 5 trays of cookies at the same time without the top ones burning and the bottom ones ending up uncooked), you can make the whole recipe at once, divide it in thirds and bake the three sponge cakes at the same time. If you can't bake them all at once, you will have to make them one by one because they are delicate and will turn out soggy if not baked immediately.

So, the first thing you need to do is weigh all the ingredients. Sift the almonds, flour and confectioner's sugar together and melt the butter. If you have a regular oven, divide the weighed ingredients in thirds. This way you will have three containers with 58 grams of egg whites in each of them, three with 42 grams of sugar, three with 127 grams of the mixture of almonds, flour and confectioner's sugar, and three with 10 grams of melted butter.

Preheat the oven to 44 F and prepare a silpat or a piece of parchment paper on top of a baking sheet. Now we will make the joconde. If you can bake the three sheets at the same time, follow the directions the the whole quantities. If not, follow the directions with one third of the ingredients, and repeat three times. First, beat the egg whites with an electric mixer fitted with the whisk attachment until stiff peaks form. Add the granulated sugar and keep beating for another minute. Stop the mixer, add the eggs and whisk in for about two seconds (the egg won't be fully incorporated into the egg whites, but it's okay).

At this point you will have to work fast but gently to prevent the dough to deflate. With a rubber spatula and a folding motion, mix the egg and the egg whites. Add the almond, flour and sugar mixture, and fold the mixture gently. Pour the dough on the silicone mat/parchment paper you prepared before and spread it with a large offset spatula. Level the dough, trying to smooth it out as much as possible working fast and trying not to overwork the dough. The edges don't have to be perfect, as we will be cutting them later on.

Bake the joconde until lightly golden, about five minutes. Remove from the oven and place the mat/paper on a wire rack to let cool. Once the cake is cold, flip the silpat and peel it from the cake. Reserve on a piece of parchment paper. Repeat the procedure with another third of the ingredients and then again with the remaining third. Now you should have three spongy joconde sheets.

Syrup

Ingredients

250 g sugar
250 g water

Procedure

Mix water and sugar, boil and let cool.

Chocolate Cream

Ingredients

50 g cocoa powder
250 g milk
6 egg yolks
180 g sugar
350 g butter

Procedure

Dissolve cocoa powder in milk and place on a heating pan. Whisk the egg yolks with the sugar until whitened. Pour the yolks into the milk and heat until the mixture reaches 85 ºC (be careful not to overheat it or you will get scrambled eggs!) Whisk the milk and yolks on an electric mixture with the whisk attachment at full speed until cooled. Add the softened butter a little at a time and keep whisking until a cream texture is obtained.

Chocolate Ganache

Ingredients

300 g whipping cream
250 g semisweet chocolate

Procedure

Chop the chocolate and boil the whipping cream. Pour one third of the cream over the chocolate, and mix with a whisk.

Add another third of the cream, and keep whisking.

Add the last third of cream and whisk until the texture of the ganache is homogeneous. It should look something like this:

Cover with plastic wrap and let cool.

Chocolate Gelée

Ingredients

60 g (2.1 oz) pure cocoa
120 g (4.2 oz) cream
140 g (4.9 oz) water
180 g (6.3 oz) sugar
4 gelatin leaves

Procedure

Hydrate the gelatin leaves for then minutes in cold water. Heat water, sugar and cream. Add cocoa and bring to a boil. Let the mixture simmer for about a minute. Pat the gelatin leaves dry with paper towels, as any water will make the gelée lose shine. Add the gelatin to the chocolate mixture, strain it through a fine sieve to prevent lumps, cover with plastic wrap and reserve.

Assembly

Ingredients

Semisweet chocolate
Butter

Procedure

Melt a small amount of semisweet chocolate and spread a thin layer over the top side one of the joconde sheets with an offset spatula.

Place in the freezer until the chocolate is hardened. The chocolate layer will be the bottom part of the cake and it will prevent it from sticking to the plate. Remove the sheet from the freezer and place, chocolate side down, on a piece of parchment paper and place on a tray that will fit inside your freezer.

Spoon syrup generously over the sponge cake and let it seep in.

Place chocolate cream over the joconde. The texture should be something like this.

Spread it creating a thick, homogeneous layer.

Place a joconde sheet on top (top side down, porous side up), cover with parchment paper and press gently with a tray so as to even out the chocolate cream. Once more, spoon syrup over the sponge cake and wait for it to seep in. Place the ganache over the sheet. The texture should be something like the one on the picture below. If your ganache is too runny, you can pop it in the freezer for a couple minutes to harden it. If it is too thick, you can heat it up a bit so you can spread it better.

Place the last of the sheets (top side down) on top of the ganache, cover with parchment paper and gently press with a tray. Spoon syrup over the last layer and let it seep in. Spread a thin layer of softened butter with an offset spatula, making it as smooth as possible. Put the assembled cake in the freezer.

Recover the gelée and heat it up until it covers the back of a spoon thickly but smoothly (about 78 F). Remove the cake from the freezer, peel it off the parchment paper and place on a wire rack over a tray. Bathe the cake with the gelée and let it set. I love this gelée. It's so shiny you can see my camera reflected on it.

Prepare the plate you want the cake to be served on, a clean and damp cloth, a sharp knife and something with a flame (I used a kitchen torch). Heat the knife, and cut the cake. For every new cut, clean the knife and reheat it with the flame. Transfer the cut cake to the plate and enjoy! When serving, use the heated knife and the cloth or else it will be very hard to serve.