nigella's quadruple chocolate cake

This is a chocolate cake recipe that I found on Nigella Lawson's very pretty site. While I have most of her books, I hardly ever seem to cook from them anymore, though I don't really know why that is. I suppose I'm just using other books as my reference points at the moment. Tessa Kiros, Hugh Fearnly and more robust recipes that do not need as much exact temperature control for good results. I'm slowly coming to grips with my range cooker where the cooking is more intuitive than an exact science, but 'twas a chocolate cake I was after, so I gave this recipe a whirl.

As far as chocolate cakes are concerned this one is a bit misleading. The four kinds of chocolate don't really make for a very chocolatey cake. There is just 50g of cocoa powder in the sponge, the chocolate chips don't add a lot more at just 175g. One more tablespoon of cocoa in the syrup and some grated dark chocolate over the top brings us up to the four kinds of chocolate that give the cake it's name. What you actually get is a very dense everyday kind of chocolate cake, and because it is so nice and squidgy will keep nicely for a week if not longer.

I have included Nigella's instructions as they appear in their entirety here. When I made it, I served the syrup separately as the sponge was already so sticky that poring the syrup over the cake just seemed wrong. It would also have made it difficult to store it anywhere except the tin I had baked it in. The recipe also requires you to line the tin with foil without tearing it. This was quite frankly, impossible, so with a pile of torn tin foil on the floor I turned to baking parchment which did not tear and worked perfectly.

I also must offer a translation for Nigella's introduction to the cake as some of you may not be able to understand her accent.

Nigella says...
This cake is not named for the bypass you might feel you'd need after eating it, but in honour of the four choc-factors that comprise its glory: cocoa to make the cake; chocolate chips or morsels to fold into it; a chocolate syrup to drench it once out of the oven; flakily sliced dark chocolate to top it before slicing.

I love this for tea, even for weekend breakfast, or late at night when its melting squidginess tends to fall darkly on to my white sheets - and I don't care. It's always wonderful as a pudding: put it on the table, ready to slice, alongside a bowl of strawberries and another of creme fraiche.

Nigella means…
I called this cake quadruple chocolate cake because it's got four bits of chocolate in. I eat it anytime I want, even in bed because I have a cleaner. I like pudding.

For the Cake:
200g plain flour
1/2 teaspoon bicarbonate of soda
50g cocoa
275g caster sugar
175g soft unsalted butter
2 eggs
1 tablespoon real vanilla extract
80ml sour cream
125ml boiling water
175g dark chocolate chips (unless you'd prefer milk chocolate ones)

For the Syrup:
1 teaspoon cocoa
125ml water
100g caster sugar
25g dark chocolate (from a thick bar if possible)

Method 
Makes 10 generous slices

Take whatever you need out of the fridge so that all ingredients can come to room temperature.

Preheat the oven to gas mark 3/170°C, putting in a baking sheet as you do so, and line a 900g loaf tin (mine measures 21x11cm and 7.5cm deep and the cooking times are based on that) with greased foil - making sure there are no tears - and leave an overhang all round. Or use a silicone tin.

Put the flour, bicarb, cocoa, sugar, butter, eggs, vanilla and sour cream into the processor and blitz until it's a smooth, satiny brown batter. Scrape down with a rubber spatula and process again while pouring the boiling water down the funnel. Switch it off then remove the lid and the well-scraped double-bladed knife and, still using your rubber spatula, stir in the chocolate chips or morsels.

Scrape and pour this beautiful batter into the prepared loaf tin and slide into the oven, cooking for about 1 hour. When it's ready, the loaf will be risen and split down the middle and a cake-tester, or a fine skewer, should come out clean. But this is a moist cake, so don't be alarmed at a bit of stickiness in evidence; rather, greet it like a friend.

Not long before the cake is due out of the oven (when it's had about 45-50 minutes) put the syrup ingredients of cocoa, water and sugar into a small saucepan and boil for 5 minutes. You may find it needs a little longer - what you want is a reduced liquid, that's to say a syrup, though I often take it a little further, so that the sugar caramelizes and the syrup has a really dark, smokey chocolate intensity.

Take the cake out of the oven and sit it on a cooling rack and, still in its tin, pierce here and there with a cake tester. Then pour the syrup as evenly as possible over the surface of the cake. It will run to the sides of the tin, but some will have been absorbed in the middle.

Let the cake become completely cold and then slip out of its tin, removing the foil as you do so. Sit on an oblong or other plate. Now take your bar of chocolate and cut with a heavy sharp knife, so that it splinters and flakes and falls in slices of varying thick- and thinness. I've specified a weight, but judge it by eye - when you think you've got enough to scatter over the top of the loafcake, stop slicing. Sprinkle these chocolate splinters over the top of the sticky surface of the cake.