Ingredients

• 100g good-quality dark chocolate (70% cocoa solids), roughly chopped
• 3 eggs
• 1 tablespoon caster sugar
• 100ml sunflower oil
• 1 cup (150g) plain flour
• 1 teaspoon baking powder
• 1/2 teaspoon bicarbonate of soda
• 1/2 cup (50g) good-quality cocoa powder
• 75g almond meal
• 300ml thickened cream
• 2 tablespoons pure icing sugar, sifted
• 440g can sweetened chestnut puree (see note), chilled

Method

• Step 1 Preheat the oven to 180°C. Grease a 22cm springform cake pan and line the base with baking paper.
• Step 2 Melt the chocolate in a heatproof bowl set over a pan of barely simmering water (don't let bowl touch the water). Remove from pan, stir gently until smooth, then set aside to cool.
• Step 3 Place the eggs in the bowl of an electric mixer and beat on high speed until combined. Gradually add the sugar, and continue to beat until doubled in volume. With the mixer still on high speed, gradually drizzle in the oil, then continue to beat until the mixture is thick enough to form ribbons when you trail it on the surface.
• Step 4 With the electric mixer on low speed, carefully pour in 100ml water and the melted chocolate. Sift in the flour, baking powder, bicarbonate of soda and cocoa powder, then add the almond meal. Gently fold into the mixture with a metal spoon so you don't lose any air. Pour the mixture into the prepared pan, then bake for 1 hour or until a skewer inserted in the centre comes out clean.
• Step 5 Remove cake from the oven and cool in the pan for 10 minutes, then transfer to a rack to cool completely. Whip the cream with the icing sugar to soft peaks, then spread over the top of the cooled cake. To decorate the cake, place the chilled chestnut puree in an piping bag with a small plain nozzle and pipe over the top of the cake in long, thin strands to form 'spaghetti'. Slice and serve.