METHOD

1. Preheat oven to 120°C (250°F). Place the butter, chocolate, sugar and water in a saucepan over medium heat and stir until melted and smooth. Transfer mixture to a large bowl and allow to cool slightly. Add both the flours, eggs and vanilla and whisk until smooth. Pour the mixture into a lightly greased 24cm-round cake tin lined with non-stick baking paper. Bake for 2 hours or until cooked when tested with a skewer. Allow to cool in the tin before turning the cake out onto a wire rack. 
   
2. Place a 20cm plate on top of the cake and use a small, sharp knife to make a 3cm-deep cut around the plate. Cut a chequered pattern of 2½cm squares in the round and use a spoon to carefully scoop out the squares. 
3. Place 2 cups of the cake squares in a large bowl and pour over ½ cup (125ml) sherry. Set aside until all the liquid has been absorbed. 
   
4. To make the custard, place the milk, cream, butter, vanilla and sugar in a saucepan over medium heat and cook until the mixture just comes to the boil. Remove from the heat. Place the cornflour and water in a bowl and mix to combine. Whisk into the hot milk mixture with the egg yolks. Return to the heat and cook, whisking, for 2–3 minutes or until thickened. Transfer to a bowl and continue to whisk until cooled slightly. 
   
5. Sprinkle the remaining sherry over the base of the cake, return the cake pieces to the hollowed-out cake with the raspberries 
and pour over the custard. Refrigerate for 2–3 hours or until the custard is set. Top the cake with the cream and extra raspberries to serve. Serves 8–10.