A special birthday cake

The “gateau Opera” for me typifies what French patisserie is all about: Elegance, sophistication, great taste, delicacy and above all a little bit of indulgence. I’ve wanted to make this cake for a while, especially after having watched it made in Martin Wishart’s kitchen on my visit of the restaurant earlier this year. But I hadn’t found the time and the right occasion until recently – my nephew’s very first birthday. Given that it was a children’s birthday in summer, I opted to diverge a little from the traditional coffee-flavoured opera for summery flavours to include Scotland’s delicious wild raspberries that have been growing in such abundance this year. In addition, my cream is flavoured with refreshing lemon and my

The cake admittedly requires a bit of planning and doesn’t travel very well. Therefore, I prepared all components (sponges, cream, sauce and ganache) in advance and transported them all individually in boxes. The final assembly took place at the location of celebration the night before and the decoration on the birthday itself. Sounds a bit like a faff but I thoroughly enjoyed planning and preparing the cake and dare I say – it was well worth it!

The following recipe is adapted from a French recipe site.

Gateau Opera with Raspberries, Lemon Cream and Chocolate

Ingredients

» Joconde sponges:

4 large eggs, 150g ground almonds, 40g icing sugar, 4 large egg whites, 40g plain flour,   40g caster sugar, 30g melted butter, a few drops of lemon

» Chocolate ganache:
200 g de sucre, 200 ml d'eau 180ml double cream, 80g milk chocolate, 110g dark chocolate, 50g softened butter

» Raspberry sauce:
80 g caster sugar, 80ml water, 100ml raspberry coulis (blended and passed through a sieve), splash of raspberry liqueur (optional) 

» Lemon cream:
2 large eggs, 4 egg yolks, 4g powdered gelatine, 120ml fresh lemon juice, 100g caster sugar, 150 butter

» White chocolate and raspberry ganache:
150ml double cream, 40g caster sugar, 50g white chocolate, 70g pureed and sieved raspberries, 4g powered gelatine, splash of raspberry liqueur (optional)

Preparation

»Joconde sponges : Whisk the eggs and the sugar using an electric whisk until tripled in size. Incorporate the almonds and the flour with a spatula. Whisk the egg whites with a pinch of salt and 4 drops of lemon juice to stiff peaks, add the sugar slowly half-way through. Incorporate the egg whites carefully to the 1^st mix.  Line a baking sheet with baking paper and dust with flour. Spread a third of the cake mixture evenly onto the tray and bake at 180°C for 12 minutes until just starting to become golden. Leave to cool for a couple of minutes, remove the sponge from the tray and repeat this step twice with the remaining dough.  

»Dark/milk chocolate ganache: Heat the cream and add both chocolates broken into little pieces. Mix until the chocolate is completely melted before adding the butter. Leave to cool.

»Raspberry sauce : Heat the raspberry puree in a small sauce pan together with the sugar and the water until the sugar has dissolved. Take of the heat and add a splash of raspberry liqueur if desired. The punch has to be used warm during assembly and can be re-heated if necessary.

»Lemon cream: Soak the gelatine in just enough water to cover the powder. Using an electric whisk, mix all ingredients with exception of the gelatine and the butter in a bowl placed into a bain-marie until the mixture starts to thicken. Incorporate the softened gelatine slowly while mixing. Take of the heat, leave to cool for a few minutes and whisk in the butter until smooth. Chill overnight.

»Raspberry/white chocolate ganache: Soak the gelatine in just enough water to cover the powder. Heat the cream, sugar and raspberry puree in a saucepan until the sugar has dissolved. Take of the heat and add the white chocolate broken in pieces. Stir well until all the chocolate has melted. Add the gelatine bit by bit while constantly mixing and the raspberry liqueur.  Leave to set in the fridge overnight.

Assembly

Melt 50g dark chocolate and spread it evenly onto the topside of the bottom sponge with a pastry brush. Leave to cool completely before turning over the sponge. This will create a seal for the entire cake. Warm up the raspberry sauce and generously brush the topside of the first sponge with it. Leave to soak for a few minutes before spreading half of the lemon cream evenly on top making sure to go all the way into the corners. Soak the bottom side of the second sponge with raspberry sauce and place on top of the lemon cream. Brush the topside of the 2^nd sponge with raspberry sauce. Leave to soak in before spreading all of the dark/milk chocolate ganache on top of the 2^nd sponge. Brush the 3^rd sponge with raspberry sauce as before and spread the remaining lemon cream onto the 3^rd sponge. Carefully layer the raspberry/white chocolate ganache on top of the lemon cream using a palate knife. If the ganache is too hard to handle, it can be warmed up a little. Chill in the fridge overnight. Trim all edges before decorating the cake to your own desire.