Great British Bake Off Technical Bake (5.4)

Desserts! Always an odd episode in my mind, as I'm never quite sure what constitutes a dessert, nor why a biscuit or a cake or a sweet bread is not a dessert, indeed, this technical bake caused a few ripples in the definition world, with comments about whether a tiramisu cake was actually, in fact, a cake, not a dessert. I digress.

This technical bake conclusively proved to me that I would struggle to cope with the pressure of the bake-off tent. I don't receive a television signal where I live (story for another day) and, therefore, watch the bake-off at a later date, in the company of The Fair Physiologist, The Pure Mathematician In Exile (when he's not at work) and their son, Little Boy Red. My contribution to this viewing is the technical bake.

Despite knowing that this family is one of the nicest around, and that, quite frankly, if a bake contains cake, chocolate and cream they will eat it, even if it doesn't meet the exacting standards required of a Bake Off Bake, I still found horizontal sponge slicing one of the most stressful things I have ever done. Just saying.

I didn't add the brandy to my tiramisu cake, because 100ml of brandy is an awful lot if you're expected to drive after eating this cake. I replaced it by increasing the amount of water used to make up the coffee, but upon reflection should have increased the coffee too, as the flavour was somewhat lost.

I also did not entirely understand the point of the crumb coat on the top layer of the cake - either this needs to be done all the way through to stop the marscapone cream and sponge from becoming one entity, or it is unneccessary, as the top layer is thoroughly covered in a thick dusting of cocoa, so you cannot see any splodgy bits of sponge anyway.

(External, after paper peeled off, sorry, no internal shots, too keen to tuck in! It was much neater inside, promise)

Having broken my thermometer whilst attempting to temper the chocolate previously (resulting in a drive to the tip clutching a bag with balls of mercury in, which the nice tip man kindly relieved me of), I merely microwaved half until melted, then stirred in the other half, which I had broken into smallish pieces. No measuring temperatures, and the chocolate was beautifully tempered, nice even snap and a lovely shine.

Recipe (from BBC Food)

Ingredients
For the sponge
a little softened butter, for greasing
4 large free-range eggs
100g/3½oz caster sugar
100g/3½oz self-raising flour

For the filling
1 tbsp instant coffee granules
150ml/5½fl oz boiling water
100ml/3½fl oz brandy
750g (3 x 250g/9oz tubs) full-fat mascarpone cheese
300ml/10½fl oz double cream
3 tbsp icing sugar, sifted
75g/2½oz dark chocolate (36% cocoa solids), grated

For the decoration
100g/3½oz dark chocolate, (70% cocoa solids), finely chopped (you do NOT need all of this - 50g would have been plenty)
2 tbsp cocoa powder

Preparation method
1. Preheat the oven to 180C/160C(fan)/350F/Gas 4. Grease a 38x25cm/15x10in Swiss roll tin and line with baking parchment.
2. For the sponge, place the eggs and sugar in a large bowl and, using an electric hand-held mixer, whisk together for about five minutes, or until the mixture is very pale and thick (here, five minutes really means five minutes, not a half hearted two and a half, you want SO much air in here). The mixture should leave a light trail on the surface when the whisk is lifted (ribbon stage).

3. Sift over the flour (the one and only time I sift flour, I just spent five minutes beating air in, I jolly well want the flour to be light too) and fold in gently using a metal spoon or spatula, taking care not to over mix (also taking care not to under mix, or you'll have blobs of flour - I think would be better to add the flour in stages, but didn't actually test this theory).
4. Pour the mixture into the prepared cake tin and tilt the tin to level the surface (again, no prodding or smoothing it out, preserve that air!).
5. Bake for 20 minutes, or until risen, golden-brown and springy to the touch (mine took nearer 30 minutes). Cool in the tin for five minutes then turn out onto a wire rack and leave to cool completely.
6. For the filling, dissolve the coffee in the boiling water and add the brandy (see note above about omitting brandy). Set aside to cool. Now is a good time to grate your chocolate if you haven't already.
7. When the sponge is cold, carefully slice the cake in half horizontally, so you have two thin sponges of equal depth (hahahaha, unless you have some sort of freaky precision cutter these sponges will not be equal depth, just be proud if they are two sponges rather than millions of pieces).
8. Using the loose base of a square cake tin as a guide, cut two 18cm/7in squares from each sponge (I found it easier to cut the squares out and then cut in half horizontally, due to the relatively short blade of my knife). You don't need the sponge trimmings for the tiramisu cake, eat them now to calm your nerves or save them for something else.
9. Line the base and sides of the square tin with long rectangles of baking parchment; there should be plenty of excess parchment which you can use to help lift the cake from the tin later (which is all well and good, but good luck getting the base parchment off the blessed thing!).
10. Place the mascarpone cheese in a large bowl and beat until smooth. Gradually beat in the cream and icing sugar to make a creamy, spreadable frosting.
11. Place one layer of sponge in the base of the lined cake tin. Spoon over one-quarter of the coffee brandy mixture. Then spread (or pipe. I wish I'd piped) one-quarter of the mascarpone frosting over the soaked sponge. Scatter over one-third of the grated chocolate.
12. Place the second sponge on top, spoon over another quarter of the coffee mixture then spread another quarter of the frosting over the soaked sponge. Scatter over another one third of the grated chocolate. Repeat with the third sponge and another one-quarter of the coffee mixture and frosting and the remaining grated chocolate.
13. Place the fourth sponge on top and spoon over the remaining coffee mixture. Using a palette knife spread a very thin layer of the remaining frosting over the top of the cake – this is called a ‘crumb coat’ and will seal in any loose crumbs of sponge. (Nope, still haven't worked out why you need this crumb coat, you won't be able to see the cream once the cocoa dusting is on)
14. Wipe the palette knife and spread the rest of the frosting in a thicker layer over the cake. Chill for at least one hour in the fridge before turning out.
15. While the cake is chilling, melt half of the chopped chocolate in a small bowl set over a pan of gently simmering water. (Do not let the bottom of the bowl touch the water.) Gently stir the chocolate until it reaches a melting temperature of 53C/127F.
16. Remove the bowl from the heat and add the remaining half of chopped chocolate and continuing stirring gently until the chocolate cools to 31C/88F or lower and is thick enough to pipe.
17. Place a sheet of baking parchment on the work surface. Use another sheet to make a paper piping bag.
18. Spoon the melted chocolate into the paper piping bag. Snip off the end and pipe decorative shapes onto the baking parchment. Leave to set until required.
19. Dust the chilled tiramisu cake with the cocoa powder (thus hiding any boo-boos in the cream), before turning out (there is no turning involved - you want the cake to still have the top at the top) onto a serving plate using the parchment paper to help lift out of the tin. Decorate with the chocolate shapes.

Now drink the brandy you didn't put in the cake.

I'm entering this in Supergolden Bakes #GBBO Bake Along and Mummy Mishaps Great Bloggers Bake Off 2014 (Desserts) .