- butter , for greasing
- 115 g plain flour
- 140 g icing sugar
- 8 large free-range egg whites
- 150 g caster sugar
- 1 teaspoon cream of tartar
- 1 teaspoon vanilla extract
- 1 lemon
- 200 g icing sugar
- 100 g butter , at room temperature
- 1 splash of milk
- hundred and thousands, to decorate
Preheat your oven to 180ºC/gas 4. Grease and line a 4-litre cake tin.
Sift the flour and icing sugar into a bowl and set aside.
In the bowl of a free-standing mixer, whisk the egg whites to soft peaks.
With the mixer still running, add the caster sugar, cream of tartar, vanilla and a tiny pinch of sea salt and whisk to stiff, glossy peaks.
Sift the flour and icing sugar again, fold it into the egg whites with a metal spoon, then finely grate and mix in the lemon zest.
Spoon the mixture into your tin (it should be about two-thirds full), tap it gently on your work surface to knock out any air pockets and smooth it level.
Bake it for 35 to 40 minutes, or until risen and a skewer inserted into the centre comes out clean.
Leave the cake to cool in the tin for 20 minutes, then carefully turn it out onto a wire rack to cool completely.
Make a buttercream icing by beating the icing sugar and butter in a free-standing mixer for 4 to 5 minutes, until pale, then mix in the milk.
Use it to cover the cake, then finish with hundreds and thousands.