- 300g dark chocolate (70% cocoa)
- 250g unsalted butter
- 7 eggs, separated
- 300g caster sugar
- ½ tsp cream of tartar
- 1 tsp natural vanilla paste
1 Preheat oven to 180C. Melt the chocolate and butter in bowl over a bowl of barely-simmering water until just melted, then set aside.
2 Put the egg yolks and 200g caster sugar in the bowl of an electric mixer and whip with the whisk attachment on high speed for 5 minutes, until light and creamy. Add the chocolate mixture and stir gently to combine.
3 Whisk the egg whites and cream to tartar to soft peaks, then add the remaining sugar and vanilla then whisk until thick and stiff. Fold gently into the chocolate mixture, ten spoon into a lined 24cm cake tin and bake for 40 minute, until risen and beginning to crack. Cool completely in the tin before un-moulding and serving.