John Whaite's Mojito cake recipe

Preheat the oven to 170C/150C fan/Gas 3.
Place the egg yolks, sugar, water and oil in a large mixing bowl and beat together until smooth.
Sift over the flour and salt and beat in along with the lime zest until well incorporated.
In a separate bowl, whisk the egg whites to stiff peaks, then fold gently into the batter.
Pour the batter into an ungreased 28cm, round, loose-bottomed tin and tap the tin lightly to expel any air bubbles.
Bake for 6075 minutes, until well risen, golden and a skewer inserted into the centre comes out clean.
Invert on to a wire rack to cool upside-down.
Make the filling by whisking the cream and icing sugar to soft, floppy peaks, before folding in the mint, and rum if using.
When the cake has cooled, remove from the tin and slice horizontally into two even layers.
Place one on a cake board or large cake stand and spread it generously with the lime curd.
Using a 10mm nozzle, fill a disposable piping bag with the cream and pipe in neat concentric circles over the curd in two layers, then top with the other cake half - I like to use the bottom half and place it upside-down so the flat bottom makes an evenly flat top.
Make the topping by beating together the icing sugar and lime juice, using as much juice as is necessary to achieve a spreadable but not too runny water icing add more icing sugar or lime juice as necessary.
Spread this on top of the cake and even out.
Finish with a scattering of lime zest.