1 Preheat the oven to 170C. Grease and line thecake tin.
2 In a saucepan over a low heat, add the chopped chocolate and the butter. Stiruntil melted and smooth. Let cool then whisk in the sugar and the egg yolks, one at a time.
3 Stir in the vanilla, the ground almonds and the chestnut puree and mix until smooth, transfer to a large bowl.
4 Beat the egg whites separately until stiff then fold through the cake mixture and bake for approximately 40 minutes or until an inserted skewer comes out clean.
