hazelnut opera cake


As the old saying goes, I’m passionate about cake. But I will steal your first born for a slice of Gâteau Opéra. Classically made with layers of almond joconde biscuit alternating with ganache and coffee buttercream, I put a little twist on mine. If I had to choose just one dessert to have for the rest of my life, this would probably be it. Having made this in the past exclusively with almond, I thought I’d switch it up a tiny bit and go for hazelnut this time. Which was a good decision.

Not too sweet at all due to the dark chocolate ganache, complemented by the most decadent mocha buttercream (and why wouldn’t it be? It starts out exactly like an ice cream). It’s funny, like most things I’ve made, I haven’t tasted any other renditions other than my own. I can’t imagine what one crafted by an authentic French patisserie would be like – my taste buds would probably go to heaven and my head would explode.


Today marks the first day of a 10-day mid-semester break which is waaaay overdue. I feel like I’m burning out and on the verge of giving up, so far am I behind with 11 hours worth of lecture content every single week. I literally cannot fathom what people who achieve higher than average grades do to keep up. They’re probably robots with microchip inserts and photographic memories. Even if I concentrate as hard as I can on what the lecturer’s saying (instead of typing up lecture notes as I usually do), I lose the train of logic about halfway through anyway. For someone who’s never missed a lecture unless absolutely unavoidable, I have to wonder whether my study methods are efficient at all.

The only plus side to this semester is that we only get one assignment across all the courses, which I suppose is pretty unheard of at uni. At least my law friends squint their eyes in envy when they count the number of assignments they have on two hands and I say we hardly have any. Still, having extra responsibilities at home for the time being doesn’t help at all trying to be organised. By the time I’ve come home from a full day of pracs and lectures and cooked dinner and cleaned up, all I can be bothered to do is kick off my boots and dive into bed.

So in the space of 10 9 days, I have to: start and finish the aforementioned written assignment, revise 2 years’ worth of clinical based content for the viva (fuck oral exams and my anxiety), re-learn and study 2 semesters’ worth of pros(thetics), somehow study 6 lectures per week’s worth of DENT2052 and revise for the anatomy prac exam which is straight after the break without any specimens to look at. Oh and freak out about the other prac exam which requires us to drill 2 cavity preps and restore one of them in 2 hours. I can barely do 1 prep and 1 restoration in one 3hr session. So yeah, I’m pretty much screwed. Every time I look at the repeating students I think about the likelihood that it could be me next year.

Rant over. Back to cake.


Hazelnut opera cake (one 13cmx30cm cake)

For the hazelnut joconde biscuit:
100g hazelnut meal
100g pure icing sugar
32g plain flour
2 large eggs
16g butter
2 egg whites (save yolks for the buttercream)
20g granulated sugar

For the mocha crème au beurre:*
150g whole milk
30g roasted cocoa beans (optional but lends subtle undertaste)
50g sugar (1)
2 or 60g egg yolks
30g granulated sugar (2)
5g instant coffee granules
165g unsalted butter, at room temp.

*I made double of what is necessary to assemble the cake because the whisk of my stand mixer wouldn’t have been able to reach such small quantities. Feel free to cut in half, though you’ll miss out on licking on the equivalent of Olympian ambrosia on Earth while you’re assembling.

For the ganache:
60g dark chocolate (at least 70%)
44g heavy cream
30g nutella

For the soaking syrup:
75g water
33g sugar
5g instant coffee
splash of Frangelico (optional)

For the chocolate mirror glaze:
5g powdered gelatin
25g water (1)
55g water (2)
33g cocoa powder
33g heavy cream
25g dark chocolate

Preheat the oven to 180C/350F. Line a sheet pan (approx. 40x30cm or similar capacity).

If you only have one mixer bowl and don’t want to wash it out, whip the egg whites and sugar together first. Otherwise, leave it till last. The meringue should be a medium peak for easy folding. Set aside.

Whip the whole eggs with the sifted icing sugar until very pale and barely drips from the whisk. Sift in the hazelnut meal and flour together and fold in carefully to incorporate. Melt the butter and cool it slightly, then add to it some of the batter until homogenous. Put the buttery batter back into the main batter and fold gently to mix. Finally fold in the meringue in 3 additions and take care to retain most of the air.

Spread the batter evenly on the pan and bake for about 15 minutes or until the middle springs back when touched lightly. Once slightly cooled, release the edges and flip upside down onto a lined surface to cool completely. Cut off the crispy edges (approx. 5mm) then into 3 equal pieces (cuts parallel to the short edge so you end up with three 13x30cm strips).

Make the buttercream. If you’d like to infuse with cocoa beans, bring the milk, 50g sugar and beans to a boil and leave to infuse for at least 10 minutes. Otherwise, just bring milk and sugar to a simmer. In the meantime, whisk together the yolks and 30g sugar until the sugar has dissolved. Slowly stream the simmering mixture (bring it back to a simmer if you left it to infuse) into the yolks while whisking the yolk mixture constantly. Then pour everything (through a sieve if there are cocoa beans) back into the pot and cook on low heat, stirring constantly, until mixture thickens enough to leave an open channel when you drag your finger through it on the back of a spoon.

Pour the mixture into the bowl of a mixer and turn it on low to release the heat. When it reaches room temperature, add in pieces of butter and increase the speed to emulsify and aerate. If it looks curdled, whip some more and it should come back to a silky smooth texture if the ingredients are all at room temp.

For the syrup, boil water and sugar together then add in the coffee and liqueur. Leave to cool.

For the ganache, heat the heavy cream until boiling and pour it on the chocolate. Leave for a minute then stir to combine. Mix in nutella and leave to cool to room temp. just so it’s spreadable.

For the glaze (finally, I know), bloom the gelatin in 25g water. Meanwhile, boil together everything but the chocolate, stirring to get rid of cocoa lumps. Turn off the heat and add the bloomed gelatin and chocolate. Stir to melt and set aside.

To assemble, take one of the biscuit strips and spread on 32g chocolate melted with 1/2 tsp neutral flavoured oil. This is just to prevent a soggy bottom. Flip it upside down so the chocolate side is down and chill briefly to set up. Brush the soaking syrup generously onto the first layer of cake. Spread on a thin layer (no more than 5mm) of half the buttercream evenly. At any point during assembly if something turns runny or feels too unstable to stack, just chill for a bit to firm up.

Layer on a second strip of cake, and brush with syrup. Spread on the ganache. Try to keep all the layers approximately the same thickness.

Place the third and final layer of cake on top, brush with syrup, spread with the rest of the buttercream as smoothly as you can as any unevenness will be visible through the glaze. Chill (not freeze) until the whole cake has firmed up all the way through.

When you’re reading to glaze, heat the glaze slightly to just warmer than body temperature. Place the cake on a wire rack on a tray and pour the glaze on top (through a sieve if it has bubbles in it), letting the excess drip off the sides. Chill until firm and cut off the uneven bits off the edges (and stuff straight into your mouth cos you bet you deserve it for all this effort).



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