Peel the courgettes (or you could use a yellow variety) if you don’t want the cake to be green. I like the colour – it goes so nicely with the pistachios on the top of the cake, but understand that green cake could be off-putting.

1. Preheat oven to gas 4/160°C. Line/grease 2×7” sandwich tins.
2. Beat the eggs and sugar together until moussey, then add all the other ingredients – I normally add the dry ones first, then the courgettes and the oil. Combine everything (carefully with a spoon, rather than whisking) and pour into cake tins. Bake for approx 35mins, depending on your oven.
3. While the cake is baking and cooling make the frosting by beating cream cheese, butter, lime juice and icing sugar together. Spread lime curd filling over the bottom half of the cake, sandwich together, then spread a generous amount of frosting over the top and sprinkle with crushed pistachios.

For the lime curd (makes around 1lb):

1. Melt the butter and sugar together first and then combine the other ingredients carefully and keep stirring briskly (I use a wooden spoon) until the mixture starts to thicken. This happens gradually – you may need to test as you would jam by putting a little on a saucer and checking the consistency. Store in a sterilised jar.