Preheat the oven to 160’C and grease and line a 24cm round cake tin.
Put your grated fruit and veg in fine sieve and push and squeeze out as much juice as you can.
Beat the egg yolk and the oil together for 3-4 minutes until smooth and creamy and then sieve in the dry ingredients.
Gently fold together and then add the courgette, apple and maple syrup.
Whisk the egg whites with the salt until it has formed stiff peaks and then gently fold this together with the remaining mixture.
Tip into the the prepared tin and level out.
Bake in the oven for 30-35 minutes until the top is springy to touch and the edges are coming away from the tin.
Once the cake is cooked, allow to cool in the tin and then tip out to cool completely on a wire rack.
While the cake it cooling, whisk together the cream cheese, syrup and lemon zest until well combined and looking lightly whipped.
Once cool, spread the icing over the top and sprinkle over the pistachios.
Slice up and enjoy!