• 250g dark chocolate (58 -70% cocoa solids), chopped
  • 250g dark muscovado (see note) or dark brown sugar
  • 60g butter, chopped
  • 60ml (1/4 cup) vegetable oil
  • 200ml Guinness
  • 1 1/2 teaspoons vanilla extract
  • 3 eggs, separated
  • 100ml buttermilk
  • 150g (1 cup) plain flour
  • 100g ground almonds
  • 1 teaspoon baking powder
  • 1/2 teaspoon bicarbonate of soda
  • Step 1 Preheat oven to 180°C. Grease a 26cm springform tin. Cut a length of baking paper to wrap around the circumference of the tin. Fold lengthwise in 3, with a 2cm overlap along one edge. Cut slits into the overlap at 1cm intervals to form a fringe. Fit paper collar into tin so the fringed part sits flat on the base. Cut a round of baking paper to fit over the base.
  • Step 2 Place chocolate, sugar, butter, oil, Guinness and vanilla in a saucepan and stir over medium heat until smooth. Remove from heat and whisk in yolks, then buttermilk. Sift over dry ingredients and whisk until just combined. Using an electric mixer, whisk whites to soft peaks and fold into chocolate mixture. Pour into prepared tin, bake for 20 minutes, then cover and bake for a further 30 minutes or until a cake tester inserted in the centre comes away with moist crumbs attached. Cool cake in tin for 20 minutes, then turn out onto a wire rack to cool completely.
  • Step 3 For filling, stir chocolate, butter and cream in a bowl over a saucepan of simmering water until smooth. Stand for 15 minutes or until thickened slightly. Combine brandy and raisins and set aside. Meanwhile, cut cooled cake horizontally into 3. Place 1 cake layer on a plate, spread with half the filling and scatter with half each of the soaked raisins and shortbread. Repeat with another layer, filling, raisins and shortbread, finishing with third cake layer. Refrigerate.
  • Step 4 For chocolate cream, bring cream to the boil in a small pan, remove from heat, add chocolate and stir until smooth. Stir over a bowl of iced water until the consistency of double cream. Spread over top and side of cake, then refrigerate for several hours to set. Bring to room temperature to serve.