1Preheat oven to moderate, 180 C. Line a 20 x 30-cm slice pan.
2Combine butter and chocolate in a heatproof bowl. Melt over a saucepan of simmering water. Cool slightly.
3Whisk yolks, half sugar and vanilla together until pale. Fold into the chocolate mixture.
4Using an electric mixer, beat egg-whites with cream of tartar until soft peaks form. Gradually beat in remaining sugar until thick and glossy. Fold meringue and meal into chocolate mixture.
5Scatter hazelnuts and raspberries over base of tray. Pour in batter. Bake 35 to 40 mins until just firm. Cool in pan. Serve dusted with cocoa and topped with extra raspberries.
Photo: Rob Shaw/BauerSyndication.com.au