superfine sugar, plus some for sprinkling
( I use caster sugar)
semisweet chocolate, chopped
( I use good quality dark chocolate)
unsalted butter, cut into pieces
confectioners' sugar, for dusting
( I use icing mixture)
- Preheat oven to 160C (325F). Generously butter a 9.5 inch (22cm) springform pan, then sprinkle with a little sugar and tap out the excess.
- Set aside 3 tbsp of the sugar. Place the chocolate, butter and remaining sugar in a heavy saucepan and cook over low heat until the chocolate and butter have melted and the sugar has dissolved. Remove the pan from the heat, stir in the vanilla extract and let the mixture cool slightly.
- Beat the egg yolks into the chocolate mixture (when cool - otherwise the eggs will cook), beating each in well, then sift in the flour.
- In a clean grease-free bowl, using an electric mixer, beat the egg whites slowly until they are frothy. Increase the speed, add the salt and continue beating until soft peaks form. Sprinkle over the reserved sugar and beat until the whites are stiff and glossy. Beat one third of the whites into the chocolate mixture (I use my electric mixer for this), then fold in the remaining whites (with a wooden spoon).
- Carefully pour the mixture into the pan and tap the pan gently to release any air bubbles.
- Bake the cake for about 35 to 45 minutes until well risen and the top springs back when touched lightly with a fingertip. (If the cake appears to rise unevenly, rotate pan after 20 to 25 minutes.) Transfer the cake onto a wire rack, remove the side of the pan and let cool completely. Remove the pan base, dust with confectioner's sugar and serve.