Via: Valéry Guédes / PR
Preheat the oven to 150°C, fan 130°C, Gas 2.
Whisk the egg yolks with the sugar and water until the mixture whitens. Add the vanilla extract.
Melt the butter and white chocolate together. Gently stir into the egg mixture. Then add the flour and salt. Beat for a few minutes. Pour in the milk little by little, whisking constantly.
Beat the egg whites until stiff and, using a whisk, gently incorporate them into the batter.
Pour the batter into the greased cake tin, smooth the surface with the blade of a knife and bake in the oven for 50 minutes. When the cake comes out of the oven it will wobble slightly.
Before turning it out, leave it to set in the fridge for at least 2 hours. Serve chilled.
To add a ganache topping, melt 150 g white chocolate then, away from the heat, add 70 ml double (full-fat) cream or whipping cream. Chill in the fridge for at least 2 hours, then whip the ganache for about 10 minutes until thick. Dust with icing sugar before serving.
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