Baking adventures with a tiny Asian wannabe pastry chef/physicist

Thursday 16 January 2014

An Ambiguous Lemon-Raspberry Gateau Opéra for My 20th Birthday


An Ambiguous Lemon-Raspberry Gateau Opéra for My 20th Birthday

Happy new year to anyone that reads this! This post has been a long time coming, and I would make the excuse that "I've been busy" or "not had access to the computer" but all of this is a lie. I've been wasting time watching every season of both Breaking Bad (greatest TV show ever made. Peep Show is a close second. And an American cooking competition show called Chopped) and Game of Thrones. And those of you who ask "after all this time?" I reply thusly:



So last year for my 20th birthday I made my own take on a gateau opéra, which traditionally is a French dessert made with 7 alternating layers of Jaconde (super light almond sponge) cake, coffee mousse and chocolate ganache. My version is similar in none of these ways and is just an opéra-like in the way that it layers of light cake (in this case a genoise sponge, my favourite sponge of all time. Subtle lemon flavour and feather-light texture), and various fillings and jams. I also added raspberries and mini meringues for a textural contrast. I believe that the inspiration for doing a take on an opéra came from the opéra episode of Great British Bake Off that was on at the time (where that lady made the beautiful but soap-reminiscent lavender and white chocolate version).

I get so much stick for making my own birthday cake every year, but think of it like so: if a designer can make her own dresses, an interior decorator can decorate his own house, why can't I make the cake that I want? I would rather you buy me more cookbooks than a cake. Each year I seem to use a genoise sponge in a different way because I love the flavour so much, I have done one set in chocolate filled with whipped cream and raspberries before, one layered with vanilla cream and coffee mousse and topped with sugar dasises, for example (also these photos show how my decorating skills have hopefully improved with practice, also it is clear that I love raspberries at this point):

 
So this recipe has a fair few processes in it, with a few ingredient lists. They can be easily tweaked with different soft fruits paired with different citrus flavours, and also made easier with shop-bought fillings such as custard or whipped cream. The only essential, unchangeable element in my eyes is the glorious sponge which is well worth making. I used to use the classic recipe from my well-used copy of Mastering the Art of French Cooking (the recipe may be in Volume 2), but I decided to take a risk and try a more modern recipe that partially cooks the eggs first to increase the stability when later whisking them to ribbon stage. I followed this recipe: http://bakersdiet.wordpress.com/2013/09/20/genoise-sponge-technical-challenge-on-the-great-irish-bake-off/. This recipe requires 13 eggs (a baker's dozen! hehe) as well so be prepared on that front! As usual key hints and tips will be highlighted in red, so off we go!

Lemon-Raspberry Mock Opéra

Ingredients: (it looks daunting but the same ingredients appear repeatedly in multiple lists!)

For the mini meringues:
- 50g caster sugar
- pinch salt
- tsp vanilla bean paste
- 1 egg white

For the cake - see above link to recipe. In with the eggs, add the finely grated zest of one lemon.

For the Italian marscapone mousse filling:
- 6 eggs
- 10 tbsp caster sugar
- 2 tsp vanilla bean paste
- 600g marscapone cream

For the lemon icing:
- 80g softened unsalted butter
- 250g icing sugar
- 25 ml milk
- 2 tbsp lemon curd
- few drops yellow food colouring

Additions:
- 3 tbsp seedless raspberry jam
- 3 tbsp lemon curd
- 1 punnet fresh raspberries
- a few squares dark chocolate (optional)

Method:

First, make the mini meringues. Preheat an oven (preferably a fan oven) to its lowest setting.


Put the egg white in the bowl of a stand mixer fitted with a whisk attachment, along with the vanilla and salt.


I tried a new brand of vanilla bean paste, and it annoyed me greatly that a teaspoon won't even fit in the jar!


By hand, whisk the white until frothy all over the surface.


Begin whisking starting on speed 1, and increasing the speed gradually over a few minutes until the "soft peak" stage is reached (when the whisk is lifted, the egg white forms a peak that folds over on itself).


Turn the speed up to high and gradually sprinkle over the sugar whilst the motor is running. Do this until the stiff peak stage is whisked (the aforementioned peak does not flop over) but the mix still is glossy looking.


Prepare a baking sheet by dotting the corners with the meringue mix and using this to adhere a sheet of baking parchment to it.


Fit a disposable piping bag with a medium star nozzle and pipe stars onto the prepared baking tray.


To pipe stars, place the nozzle of the piping bag vertically above where you want them to be and apply even pressure, lifting off and releasing pressure when finished. This technique is shown well in this videohttp://www.youtube.com/watch?v=euMWZPqnrl8

Place the meringues in the oven and leave to dry out for at least a few hours, or until crisp and easily removable from the baking parchment. When done, leave the meringues in the oven and turn it off until you need to use them. This results in minimal colouring and brilliant white meringues. If time is an issue, you can go up to 140 degrees on the oven temperature, but watch the meringues carefully in order to prevent burning. The oven door can be held slightly ajar with a wooden spoon if the heat gets too much.

I luckily have two ovens, so I could bake the cake at the same time as the meringues at a different temperature. (:

Now, make the sponge. I will not go into detail with the recipe and method as those are detailed on the link, but here are a few pictures to help!



 The eggs, sugar and vanilla mixture at the ribbon stage. When this is reached successfully, a figure of 8 drawn with the falling mixture over its own surface will hold its shape. The eggs will have at least tripled in volume.


Fold in the butter and flour alternately, starting and ending with the butter in order to minimise air loss.


Once the mixture is in the tin, tap it sharply on the work surface to get rid of any large air bubbles.

Whilst the cake is baking, make the lemon icing.


Beat the butter and sugar with an electric handheld whisk, beater on a stand mixer or wooden spoon, until it reaches a sandy consistency.


Then gradually mix in the milk.


Finish by mixing in the lemon curd and food colouring. More or less curd can be added depending on your preference.

Now, make the Italian marscapone mousse filling. Separate the eggs and add half the sugar to the whites, and half the sugar to the yolks along with the vanilla.



Whisk the whites to the stiff peak stage. 


Whisk together the yolks mixture until the sugar is dissolved.


Add the marscapone and mix until combined and smooth.



Fold the whites mixture into the yolks mixture, cover with cling film and leave aside until needed. If your kitchen is hot, you may want to leave the mousse in the fridge. This mousse is so good as a filling for cakes, trifles, profiteroles, you name it. It is just a lovely light creamy texture and not too sweet. I adapted it from an Italian recipe for tiramisu.



The baked cake! I love how light and airy it is, with that desirable pale golden colour. leave the cake to cool completely on a wire rack.


And then split it in two. This is a good video of how to split it in half: http://www.youtube.com/watch?v=Q_usTjoHAAA

Now... Prepare for... CAKE ASSEMBLY TIME!




Wash the ring of the loose-bottomed cake tin you used to bake the cake and place it in the centre of your serving plate. Put the bottom layer of the cake, cut side up, and use the back of a teaspoon to "squish" it out to the edges. Spread this layer generously with lemon curd.


Fill another piping bag with the raspberry jam and leave aside for now.


Place a border of raspberries around the edge of the cake, touching the sides of the cake tin. Try to use raspberries of the same height.



Spread half of the pre-prepared mousse onto the cake and top with more raspberries, reserving 10-15 for decorating the top of the cake.


Then spread the rest of the mousse evenly over the whole lot, levelling it as much as you can. I find a flexible flat rubber spatula is an ideal tool for this job.


Top with the other layer of cake and then spread the lemon icing on top.


For the feathered icing decoration: snip the end of the piping bag off and pipe parallel lines of jam across the top of the cake.


Drag a skewer or toothpick in perpendicular lines first in one direction, then the other through the lines of jam.


The finished mini meringues.

Set the cake for at least 4 hours in the fridge, but preferably overnight.


Before serving, decorate the cake with the reserved raspberries and mini meringues (I didn't use all of the mini meringues, but they keep well in an air tight container for a good month or so), and chocolate shavings if desired.


To unmould, use a chef's blowtorch to lightly apply even heat around the ring, say a prayer, then lift it off. If you don't have a chef's blowtorch, a kitchen cloth soaked in hot water, wrung out, wrapped around the ring and held there for a minute will do the same job.


Enjoy the cake with family and presents. (:


I hope you enjoy the recipe! It is one that I feel is well worth the effort. 

Happy baking!

Hadia