Preheat the oven to 180˚C/ 160˚C fan/gas 4.
Grease and line a 2lb loaf tin.
Coarsely grate the courgettes, then give them a good squeeze with your hands to remove as much liquid as you can. Set them aside.
Mix the sugar, oil and eggs until well beaten.
Stir in the grated courgettes.
Stir in the pistachios (keeping a small handful to one side to decorate the cake), lime zest, self raising flour, bicarbonate of soda and cinnamon.
Stir again until everything is thoroughly combined.
Pour into your prepared tin and bake for 50-60 minutes until a skewer comes out clean.
While your cake is baking you can make the frosting - you can do this by hand or in a mixer.
Beat the butter until it is smooth, light and fluffy.
Add the sifted icing sugar and beat again - start slowly, so you don’t get icing sugar all over the kitchen...
Add the cream cheese and continue beating until you have a smooth frosting. You could add a squeeze of juice from one of your limes, for an extra limey vibe.
Allow the cake to cool and then remove from the tin.
Once the cake is cold, smooth the frosting over the top of the cake and sprinkle on the reserved pistachios and perhaps a little extra lime zest.