Bitter Chocolate and Chestnut Truffle Cake with Candied Chestnuts
Bitter Chocolate and Chestnut Truffle Cake with Candied Chestnuts

Bitter Chocolate and Chestnut Truffle Cake with Candied Chestnuts

  • Prep time:

  • Cook time:

  • Total time:

  • Portion/Yield:

    Serves 10–12
  • Difficulty:

    Experienced

I use a combination of freshly roasted chestnuts and chestnut purée for this delicious truffle cake. It’s rich, sweet and ever so naughty, but definitely worth every mouthful! The inspiration for this recipe came from years of living in London. Walking along Oxford Street in November and December in the cold and damp, there was always a strong smell of roasted chestnuts combined with candied peanuts, which the street vendors used to sell. Whether I was hungry or not, I had a desire to eat them. Now, when I collect chestnuts in the forest on a chilly day, the memory of the sweet smell of roasted and candied nuts often returns. This recipe is created from those memories.

Using the best chocolate you can find is essential to ensuring the deepest, richest flavour. I recommend using a chocolate with 70% cocoa solids for the best results, as the contrast between its bitterness and the natural sweetness of the chestnuts works beautifully.photo of Bitter Chocolate and Rendelsham Forest Chestnut Truffle Cake

Ingredients & Method

For the bitter chocolate and chestnut cake base

  • 100ml dark rum 125g Roasted Chestnuts, peeled and roughly chopped
  • 5 eggs, separated
  • 100g caster sugar
  • 225g dark bitter chocolate (70% cocoa solids), broken into pieces
  • 125g unsalted butter, diced
  • 50g ground almonds

For the bitter chocolate and chestnut mousse

  • 2 leaves of gelatine
  • 2 tablespoons cold water
  • 225g dark bitter chocolate (70% cocoa solids), broken into pieces
  • 175g unsweetened chestnut purée
  • 4 eggs, separated
  • 60ml dark rum
  • 50g caster sugar
  • 200ml double cream

For the candied chestnuts

  • 250g Roasted Chestnuts, peeled
  • 1 tablespoon unsalted butter
  • 200g caster sugar

For the chocolate glaze

  • 2 leaves of gelatine
  • 110g caster sugar
  • 100ml cold water
  • 100ml double cream
  • 40g cocoa powder

First, prepare the cake base. Preheat the oven to 180°C/Gas Mark 4 and grease, then line a 28 x 18 x 4cm baking tin with non-stick baking paper. Set aside. Place the rum and chestnuts in a small saucepan and bring to the boil over a medium heat, then simmer for about 1 minute – just long enough to warm the nuts and help them to absorb the rum flavour. Remove from the heat and set aside for 10 minutes. Put the egg whites into a bowl and whisk until foaming, then add the sugar and whisk together until the mixture forms soft peaks. Set aside.

Half-fill a saucepan with water and bring up to a gentle simmer. Choose a heatproof mixing bowl that will sit comfortably over the saucepan without slipping down inside the pan, and place the bowl over the pan (you also want to make sure that the bottom of the bowl does not come into contact with the simmering water underneath). Put the chocolate and butter into the bowl and stir gently until melted and combined. Remove from the heat and remove the bowl from the pan, then stir in the soaked chestnuts and rum and the egg yolks. Using a large metal spoon, fold in the ground almonds and meringue.

Spoon the cake mixture into the prepared baking tin and level the surface. Bake in the oven for 18–20 minutes or until well risen but still soft and a skewer inserted into the centre of the cake comes out clean. Remove from the oven to a wire rack and leave the cake to cool completely in the tin. The cake will sink slightly, so use the back of a spoon to gently flatten it and even it out. Once cool, refrigerate the cake base (leaving it in the tin), while you make the mousse.photo of Bitter Chocolate and Chestnut Truffle Cake with Candied Chestnuts

To prepare the bitter chocolate and chestnut mousse, soak the gelatine in cold water until it has softened. Squeeze the gelatine gently to remove excess water, then place the gelatine in a small heatproof bowl with the measured cold water. Place the bowl over a small pan of simmering water and stir the gelatine until it has dissolved, then remove from the heat. Meanwhile, melt the chocolate in a separate heatproof mixing bowl set over a pan of simmering water (as above). While the chocolate is melting, place the chestnut purée, egg yolks and rum in another mixing bowl and use a wooden spoon to combine. Add the dissolved gelatine and melted chocolate to the chestnut purée mixture and stir to mix.

In a separate bowl, whisk the egg whites until foaming, then add the sugar and whisk together until the mixture forms soft peaks. Whip the cream in another bowl until it forms soft peaks. Fold the meringue and whipped cream into the chocolate mixture using a metal spoon, until well combined, then spoon the mousse evenly over the chilled cake base in the tin and level the surface. Refrigerate for about 6 hours or until completely set, before glazing.

Meanwhile, make the candied chestnuts. Line a baking tray with non-stick baking paper and set aside. Cut the chestnuts into quarters. Melt the butter in a non-stick saucepan and once it starts to foam, add the sugar and chestnuts and heat gently, stirring to dissolve the sugar. Increase the heat and boil the mixture until it turns a golden brown caramel colour and is thick and sticky, stirring regularly (stirring will help to encourage crystallisation and a fudge-like texture). Pour the candied crystallised chestnuts on to the prepared baking tray. Leave to set and cool completely at room temperature, then break the candied chestnuts into smaller pieces and store in an airtight container until needed (see Cook’s Notes).

Make the chocolate glaze. Soak the gelatine in cold water until it has softened. Place the sugar, water and cream in a small saucepan and heat gently, stirring to dissolve the sugar, then bring to the boil over a high heat and boil rapidly for 2 minutes. Stir in the cocoa powder and boil over a high heat for a further 1 minute. Remove from the heat and set aside to cool at room temperature, until the glaze is considerably thickened and nearly set, then pour it evenly over the set mousse. Return the cake to the fridge for about 30 minutes to allow the glaze to set completely.

To serve, cut the cake into slices using a warm, sharp knife, then carefully remove from the tin. Place a slice on to each serving plate and decorate with the candied chestnuts. Serve immediately with cream or crème fraîche.

Cook’s Notes

The candied chestnuts can be made up to 3 days in advance. Store them in an airtight container in a cool, dry cupboard.

Any leftover truffle cake can be stored in an airtight container in the fridge for up to 3 days.