Caramel and Apple Opera Cake

This week my parents came over for dinner, providing a perfect opportunity to try out another dessert from The Great British Bake Off, as part of The Great Bloggers Bake Off. The choices from the semi-final program were a Charlotte Royale ‘brain cake’ from the technical challenge, or a rather more appealing layered Opera cake. Easy choice.

The Opera cake recipe is pretty much the same all over the web – for the basic Joconde (almond) sponge at least. My recipe was based on this one over on BBC Food. However on reading through, my baking tins were not 18 x 13 inches as they’d used – so I scaled it down to 2/3 to fit with my 14 x 11 inch tins, which are your standard kitchen baking trays.

Ingredients – Joconde sponge

4 egg whites (you can use the yolks in a french buttercream, see below)
18g sugar
150g ground almonds
150g icing sugar
4 eggs
55g plain flour
58g butter, melted

Method

– Beat the egg whites to a soft peak stage, and add the sugar to form a stiff peak meringue mixture
– In a separate bowl, beat the eggs, ground almonds and sieved icing sugar for about 5 minutes, until roughly double the size
– Fold the egg whites gently into the almond mixture, before folding in the melted butter, a couple of spoonfuls at a time
– Spread the mixture into 2 tins – approx. 14 x 11 inches, lined and well greased. Ensure it fills up the corners
– Bake at 220 degrees for 5 – 7 minutes, until lightly golden on top and springy to the touch
– Remove from the oven and carefully peel off the paper. I found cooling on top of another sheet of baking paper helped move them around during assembly. Slice in half and fill.

To fill

– Buttercream – french or otherwise! My attempts at French buttercream weren’t great, but it’s a great way to use the leftover egg yolks, and is the perfect complement to the almond sponge.

– Syrup to moisten the sponges

– Ganache, or caramel in my case

– Chocolate, to top

I borrowed some great tips from Joe Pastry for this bake as a whole. One of the best ones being covering the bottom sponge white another layer of chocolate, so it wouldn’t stick to the plate and would be easier to slice. Cool with the chocolate face down on a layer of greaseproof paper.

To moisten each layer of sponge, I made a caramel apple syrup. 2 apples, chopped (I didn’t peel them, the red skin added to both the colour and flavour), boiled in a saucepan on a medium heat with 1 tablespoon of water and 60g brown sugar, stirring to prevent sticking and burning, for 5-10 minutes, until the apple turns into a mushy puree. I added a couple of tablespoons of amaretto and left to cool, sieving, and spreading on each layer before adding the fillings. Another good tip I picked up was to have the cake facing upwards as it had baked, as the top is more porous than the bottom.

For the bottom layer of my cake, I used a spiced apple buttercream. Chopping the apple into small pieces, I microwaved it for a few minutes to remove most of the water, and soften to a stiff puree. When cool this was beaten with 30g butter and about 75g icing sugar – enough to make a stiff paste, and flavoured with 1/2 teaspoon of cinnamon and a pinch each of ginger and nutmeg.

In the centre – a gooey caramel. I used about half a can (200g) of ready made dulce de leche, available in the supermarket, or you can make your own.

And the top section, some caramelised, spiced apple chunks for a bit of texture – 2 apples chopped and heated in 30g brown sugar, a teaspoon of water and a little cinnamon, for just a few minutes to soften.

I topped these with my no-so-great attempt at French buttercream. Made using egg yolks, a boiled sugar syrup, and butter, all whipped to (supposed) perfection, I think my problem came with not testing the sugar syrup temperature / texture, so it may not have been cooked enough. I followed this lovely recipe and simple steps, it looks so easy in the pictures!
Nevertheless whilst building my other layers, I found it was starting to set in the fridge, so chanced using it on this top layer. It was a bit thin but did add a certain something taste wise.

Finally, my chocolate topping. Having a tableful of guests waiting for dinner I had no time to temper it, but honestly don’t think it mattered! I used around 150g of white chocolate although could have got away with a bit less.

At this point the cake was a little oozy – mostly from the French buttercream – but half an hour in the fridge did wonders!

And to finish – decoration with more white chocolate.

The edges needed a quick trim to neaten them up – this is best done with a hot knife (run under hot water and dry), so as to get a smooth cut and not stick to any of the layers. This end wasn’t so straight – Paul Hollywood wouldn’t be pleased!

And finally ready to serve – some websites suggest edible gold, I opted for a sprinkle of iridescent edible glitter for that shimmering touch.

Again sliced with a hot knife, and I was so happy with how the layers looked inside!

It was a lovely showstopper of a dessert, quite rich, but very well received. As for the 4+ hours spent in the kitchen making and assembling – lovely as it was, I think this might be a one off!

See more attempts at this weeks GBBO challenges over at the Great Bloggers Bake Off with Helen and Jenny.