I have been wanting to make this cake for a while but I knew that I would involve committing several hours to the cause. Music on, all equipment assembled and at the ready: I set to. It is an absolute stunner – definitely an OMG wonder of a celebratory cake! A sheer pleasure of many layers, your tastebuds are delighted first by rich chocolate, then by the light, zesty orange butter cream, then by the gentle warmth of cardamom and the intense, distinctive taste of pistachios, returning finally to the rich chocolate. John Whaite may call it ‘Opera Cake’, but to me it’s a glorious diva – requiring a huge amount of attention but worthy of it given the integral gift of enjoyment it exudes! If you have the time and want a real show-stopper of a cake, this is it! Don’t be put off by the long list of ingredients or instructions: it’s just like having five mini recipes for one ultimate creation – worth every second!
Makes 18 good-sized slices
What you need…
2 x 20 x 30cm Swiss roll tins, buttered and lined with parchment paper
5 egg whites
100g pistachios, ground (in your food processor)
50g ground almonds
150g icing sugar
40g unsalted butter, melted
for the ganache
8 cardamom pods, bruised
200g dark chocolate, roughly chopped
20g unsalted butter, room temperature
for the syrup
60g caster sugar
4 cardamom pods, bruised
Juice from 1 large orange
for the orange buttercream
75ml unsalted butter, room temperature
Zest from 1 large orange
150g icing sugar
1 teaspoon fresh orange juice
to decorate with chocolate mirror glaze
1 gelatine leaf
120g golden caster sugar
1 tablespoon golden syrup
75g cocoa powder, sifted
60ml double cream
Gold leaf (optional but opulent!)
What to do…
Preheat your oven to 200°c / 400°f / gas 6.
Into your processor tip in the eggs, pistachios, almonds, icing sugar and flour. Whizz until well combined.
Using a handheld electric whisk, beat together the egg whites in a mixing bowl until stiff peaks are formed. Tip in one third of the sugar and whisk in thoroughly before repeating with a second third and then the remaining sugar.
Onto the egg whites, gently pour the pistachio mixture and the melted butter. Using a balloon whisk, gently fold together so that all three elements are evenly incorporated.
Pour into your two Swiss roll tins, smooth surfaces and pop in the oven for 12 – 15 minutes or until light golden brown and springy to the touch. Remove from the oven and cool completely in their tins whilst you make the ganache, butter cream, syrup and glaze.
For the indulgent ganache, pour the milk into a saucepan with the 8 cardamom pods, set over a high heat until the milk begins to steam and then remove from the heat, allowing the cardamoms to infuse for 10 minutes.
Pop your chopped chocolate into a heatproof bowl.
Remove the cardamom pods and then heat the milk until bubbles start to form around the sides. Pour the milk over the chocolate and after 30 seconds, use your balloon whisk to beat like crazy until the chocolate is melted. Add in the butter and whisk until all is incorporated and is lovely and glossy. Set aside.
Place the sugar, water and 4 cardamom pods into a saucepan and bring to the boil over a high heat. Boil for 3 minutes. Allow to cool a little. Add the orange juice and set aside.
In your food processor, tip in the butter and orange zest. Whizz until evenly mixed. Add the icing sugar and orange juice. Whizz until pale and light. Set aside.
Soak the gelatine leaf in a bowl of cold water for 5 minutes.
Meanwhile, heat the sugar, water and golden syrup in a small saucepan. Bring to the boil and simmer vigorously for 2 minutes. Remove from the heat and, using a balloon whisk, beat in first the cocoa powder and then the cream. Return to a moderate heat for 1 minute, stirring constantly.
Remove from the heat. Squeeze the excess water from the gelatine and add to the chocolate mixture. Stir until dissolved. Sieve into a jug and set aside.
Here we go – time to assemble – this bit is really relaxing and I loved seeing it all coming together.
Carefully remove your sponges from the parchment paper and from each one, cut a 20cm square, also giving you a 20cm x 10cm rectangle.
Take a 20 x 20cm sponge and put it on the board or plate that you intend to serve this glorious diva of a cake on. Using a pastry brush, apply the syrup to the sponge, using about one third. Then, spread two-thirds of the ganache evenly over the top. Pop the sponge in the freezer for 5 minutes. Clear up a bit.
Place the two rectangular sponges on the ganache to create the second 20 x 20cm square sponge layer. Apply half the remaining syrup all over the top and then spread over all of the buttercream. Pop in the freezer for 5 minutes. Clear up a bit more.
Take the remaining square sponge and evenly apply the remaining syrup all over. Flip it (so that the syrup is on the underside) and gently place it on top of the buttercream. Spread the remaining ganache over the top and then pop the cake back into the freezer for 20 minutes. Clear up a lot!
The glaze needs to be runny so pop it in the microwave for 30-second bursts until it is glossy and runny again. Enjoy gently pouring it evenly over the chilled cake, making sure the whole surface is covered. Put back in the freezer for 30 minutes until set.
To serve, first a little tidy up of the diva, so it looks its absolute best! Fill a tall jug with boiling water from the kettle and arm yourself with your sharpest knife. Dip the knife in the water, dry and then trim one side of the cake by just 5mm to create a sharp edge with beautifully defined layers. Repeat the dip, dry and trim process for the remaining three sides and then again to divide the cake up into either smaller cakes (I made 3 smaller rectangular cakes, each serving 6 slices) or slice up the whole lot. Decorate with gold leaf if you’re feeling opulent or simply indulge in the loveliness that is this fabulous cake!
It absolutely WAS worth the effort! Enjoy!!!!
Freeze the left over egg yolks from the biscuit sponge – you only need one more to make a fabulous and large Tiramisu (recipe to follow).
Rinse and dry food processor bowl, balloon whisks and saucepans as you complete the first stages to reduce the final washing up pile!
2012 Great British Bake Off winner, John Whaite
It’s not a difficult recipe but it does take hours and my kitchen looked like a bombsite during the process. Called into play were the food processor, mini chopper, electric hand whisk, juicer and mixing bowls as well as three balloon whisks, jugs and countless spatulas, knives and spoons. I am a messy cook anyway but wow! this was a whole new level of kitchen mayhem, even for me. Saying that, during the cake assembly, when it is popped into the freezer for a few sessions, the dishes, surfaces and equipment gradually got washed, wiped down and returned to normal so when this glorious cake was finished, it was centre stage in a spotless kitchen with only the whirring of the dishwasher as a gentle reminder of the havoc that had reigned!