Celebrating the Bake Off: Opera Cake
I’ve been so absorbed in the Tour de France for the past few weeks that I didn’t notice that the Bake Off was coming. I was thinking about taking a break from baking this week, or perhaps making something simple, something like ginger biscuits, or blueberry muffins to see if homemade were better than Tesco’s Own (ginger biscuits) or Starbucks’ (blueberry muffins). Then I saw the trailer for the Bake Off. There was only one thing I could do. Attempt a Great British Bake Off Big Book of Baking show stopper. I decided on the Opera Cake.
The Opera Cake is a three spooner on the Big Book of Baking difficulty scale. There are four pages of instructions, and step-by-step pictures showing you how to assemble it. It must be hard. The cake is a square, three-layer sponge. The sponge is soaked in a coffee and brandy syrup, and the layers are sandwiched together with coffee buttercream and chocolate ganache. The cake is then covered with a chocolate glaze with the word “opera” and other “elegant” – to quote the recipe – dashes and dots piped onto the top. The Big Book of Baking also suggests using edible gold leaf to finish. It was a big leap from thinking about having a week off to deciding to make this cake.
Making Cake Cases
The first step was to make cases for the sponge. I’m not sure why ordinary cake tins won’t do, perhaps it has something to do with the size of the cake. Anyway, the recipe tells you to make three 25cm square cases from parchment-lined foil. They didn’t have any in Tesco. I knew they wouldn’t. I don’t know why I bothered to make the trip to find out. To make my cases I folded foil around squares of baking parchment. It was a bit fiddly, but it did work.
Next was the sponge cake. It’s a whisked sponge made with egg whites and cream of tartar whisked to soft peaks and then to a glossy meringue with caster sugar. The cakey bit is made by whisking eggs, icing sugar and ground roasted hazelnuts together until the mixture is thick and, according to the recipe, massively increased in volume. This should take about 4 minutes apparently. I had to whisk for a lot longer. My mixture had increased in volume, but it didn’t seem that thick. I whisked for around 10 minutes. Perhaps I should have increased the speed of the KitchenAid, but I’m a bit concerned that if it goes any higher than level 6 it will jump off the work surface and bite me.
After 10 minutes of whisking, I folded in plain flour, then the meringue and, finally, some melted and cooled butter. I put the mixture into my cases (which were on baking trays) and into the oven at 200° fan. Although it’s a fan oven, the sponge on the top rack was cooked before the bottom. It took 8 minutes. I gave the bottom sponge another three.
Once the cakes came out of the oven I turned the baking trays onto a wire rack covered with baking paper – just baking paper, not foil-backed, not non-greaseproof, just plain baking paper, and peeled off the cases. This was tricky but I managed it without leaving too much of the cake behind. I left them to cool, then wrapped them up in a mixture of clingfilm and baking paper where they would stay until I started Project Cake Assembly.
I was one and a half pages through the four page recipe. Next, I turned to the coffee syrup. I dissolved caster sugar, instant coffee, and water, simmered the mixture for a minute and stirred in a tablespoon of brandy. Easy.
After the syrup, I made the chocolate ganache filling. I heated whipping cream until it was steaming, and poured it over a bowl of dark chocolate. I have made chocolate ganache before (when I made grasshopper slices) and had trouble melting the chocolate with hot cream. This time, I chopped my chocolate very finely and used a small bowl. This worked. The chocolate melted away. I stirred in some butter, covered the ganache, put it into the fridge and went to bed. This is definitely a two-day cake.
I’d decided to leave the coffee buttercream until Day Two. I had to boil sugar. The last time I made butter cream with sugar syrup I had a nightmare) so I thought it would be best to tackle it after a good night’s sleep. I dissolved caster sugar in water and boiled it until it reached 115° – this is marked as “soft ball” on my sugar thermometer.
While the sugar was heating up, I whisked two egg yolks in the KitchenAid and added the sugar once it had hit the magic 115°. The recipe says that you have to be careful when you pour the syrup in and make sure that it doesn’t trickle down the side of the bowl. I see why. As soon as it hits, the syrup solidifies. I think I got most of it into the bowl, but I certainly had a bit of a sugary crust around the outside. Anyway, I whisked the mixture until it was cold, then added some softened butter and instant coffee which I’d dissolved in boiling water. I whisked again until the mixture was smooth. A successful buttercream.
So, now to assemble the cake. I had a slight problem. I’d taken the ganache out of the fridge before I started on the buttercream, but it hadn’t warmed up enough to be spreadable. I decided to give a quick blast in the microwave. When I took it out, it was too sloppy to be spreadable so it went back into the fridge and I was back to square one. While it was cooling down again I got on with the first layer.
I put one of the sponges crust-side up on a piece of baking paper and covered it in a layer of melted dark chocolate. Once the chocolate had set, I turned the cake over and brushed the other side with the coffee syrup and left it to soak for ten minutes. I then spread three-quarters of the buttercream over the cake, put another layer on top of it (crust-side down) and soaked that in coffee syrup. Then I had a break (the ganache wasn’t quite firm enough yet).
No Home and Away for me this week (although I have sixty-odd episodes to catch up on). It was Friday morning and the Edgbaston Test was on, Australia were knocking the ball all over the ground in a desperate attempt to give England a half decent figure to chase. Today, it had to be Test Match Special. No contest.
Once my chocolate ganache was spreadable, I put the lot onto the second sponge, put the third sponge on the top and, again, soaked it in coffee syrup. The last of the buttercream went onto this sponge in a thin layer, the cake went into the fridge, and I started to make the top glaze.
The glaze for the cake is made from chocolate melted in clarified butter. I’m not sure whether I clarified the butter correctly (in fact, I’m sure I didn’t). The recipe says that you melt the butter in a pan, skim off the foam and pour the clear butter into a bowl. I seemed to have an awful lot of milky white stuff to skim off, and not very much clear butter, so I “filtered” it through some kitchen paper. Not sure what Mary and Paul would have to say about that.
Anyway, the “filtered” butter looked pretty clear so, as per the recipe, I heated it up again and poured it onto chopped dark chocolate. The chocolate didn’t all melt, so I put the bowl over some warm water until it had. Again, I’m sure you’re not supposed to do this, but the glaze looked pretty glossy so I wasn’t too worried.
I got the cake out of the fridge and poured the glaze over the top (the cake was still on a sheet of baking paper). It looked great until I decided to help the glaze along a bit with a knife. I left a bumpy patch in one corner. I resisted the temptation to try and smooth it out. Once the glaze covered the top of the cake, it went back into the fridge.
The last leg. Once the glaze had set, I used a hot knife to trim the edges. The cake had to be a neat square. There were enough off-cuts to see me nicely through the afternoon. I melted some chocolate and managed to pipe the word “opera” onto the top. I also managed a treble and bass clef. I’m not sure I’d call them “elegant” as required by the recipe though. I haven’t used edible gold leaf. That’s another thing there’s no point looking for in Tesco.
Here is my opera cake.
Was it worth it?
I’m pretty pleased with it. The glaze could be a bit more shiny though (the trick must be in the clarified butter). I know that it tastes good – at least it does around the edges. I’ve also left the cake on the baking paper, rather than moving it to a cake board as suggested by the recipe. I need one of those big circular paddle things for cake moving. I only have a fish slice.
Even though it looks and tastes good, the Opera Cake was a lot of effort. I’m not sure it was worth two day’s work. Hats off the Bake Off contestants who have to make things like this in a couple of hours. No wonder their hands start to shake and things start to go wobbly. Can’t wait ’til Wednesday…