Chestnut chocolate cake: Nailed

I spent most of February in a clatter of pans and a blizzard of chopping, stirring and whisking as I devised recipes for my friend Mark's new book, A Taste of the Unexpected. Actually, that’s not strictly true. Mark and I did seem to spend a lot of time on the phone gossiping about important stuff like 80s music, biscuits and football. We both support red teams, though not the same ones, so it made for lively, deadline-diverting, conversations.

One of our recipes is for a chestnut jam. It’s bloody good. It better be. It requires the peeling of 2kg of chestnuts. (Mark, don’t think I’ve forgotten. I am invoicing you for a manicure.) It was worth it though as the result is a fudgy, creamy, seductive combination of nuts, muscovado sugar, vanilla and a splash of apple cider brandy at the end because, well, how can that ever be a bad thing? I wish I could share it with you here, but I can’t. Not quite yet. You’ll have to wait until its publication in September. Just in time for chestnut season, in fact.

I have four jars of this heavenly concoction in the cupboard and I was dying to use some in a recipe. The obvious candidate was the flourless chestnut and chocolate cake in Hugh Fearnley-Whittingstall’s The River Cottage Year. I’ve made it dozens of times, every time I want an easy, delicious slightly grown up chocolate cake in fact. It has a wonderfully light texture – it’s like a rich, silky mousse in cake form - perfect for afternoon tea or a divinely seductive ending to a great dinner. And another bonus? If you’re the self-controlled sort, it last really well in an airtight tin for four or five days.

I used 400g of our jam in the recipe. Until I’m allowed to share, you could use 400g of bought chestnut jam or just follow the instructions for making the chestnut puree below, perhaps adding half a teaspoon of vanilla extract and a teaspoon of brandy too if you like. At least you’ll get to enjoy the cake without pursuing Mark to sort out your tab at the nail bar. You’d have to explain what a nail bar was to him first anyway, and that could get tiresome.

River Cottage chestnut and chocolate cake

250g dark chocolate
250g unsalted butter
250g peeled and cooked chestnuts (I like Merchant Gourmet)
250ml milk
4 eggs
125g caster sugar

Preheat the oven to 170C/325F/Gas mark 3. Butter a 25cm cake tin and line with baking parchment.

Break the chocolate into pieces and place them in a heatproof bowl with the butter, cut into chunks. Place the bowl over a pan of barely simmering water until melted and stir until smooth. Cool slightly.

In another pan, heat the chestnuts with the milk until just boiling, then mash thoroughly with a potato masher or puree in a blender.

Separate the eggs and put the yolks in a bowl with the sugar. Mix until well combined then stir in the chocolate and the chestnut puree until you have a smooth, blended batter.

In a separate bowl, whisk the egg whites until stiff and then fold them into the chocolate mixture, starting by mixing in a third of the whites to loosen the batter and then gently folding in the rest of the whites. Pour and scrape into the cake tin then bake for 25-30 minutes, until it is just set but still has a slight wobble.

If you want to serve the cake warm, leave it to cool a little, then release the tin and slice carefully – it will be very soft and moussey. Or leave it to go cold, when it will have set firm. Serve with a trickle of double cream, especially when warm, but it also delicious unadulterated.