Preheat oven to 160°C. Line 26cm spring form cake tin with baking paper.
For cake, combine chocolate and butter in a bowl over a saucepan of simmering water.
Once chocolate has melted, remove from heat and cool slightly
Beat egg yolks with whisk and add 225g of the measured sugar until well blended. Fold into chocolate mix and stir in sifted flour and hazelnut meal.
In an electric mixer, beat egg whites and remaining sugar until soft peaks form. Fold egg whites gently but thoroughly into chocolate mixture.
Pour into cake tin, and bake for one hour.
For coulis, place raspberries and sugar into saucepan and bring to the boil. Reduce heat and simmer for approximately ten minutes, stirring occasionally, until the mixture starts to thicken
Press mixture through a fine mesh strainer, using a spatula to extract as much of the liquid as possible. Discard skins and seeds. Stir in lemon juice.
Serve slices of cake with raspberry coulis and double cream