In a medium sized metal bowl, combine the kaffir or regular lime zest with the sugar for the curd. Massage it together with your fingers to release the oils, and set aside.
Preheat the oven to 180 degrees Celsius, and grease and line a springform tin (mine is 20cm - grease 2 if you are double batching the recipe)
Place the sugars, eggs and olive oil in your kitchen mixer with the beater attached, and beat until the mixture is light in colour and almost like a cake batter consistency.
While that is happening, grate the zucchini with the large side of the grater, and place it into a sieve. Using your hands or a clean towel, wrap it up and squeeze all the life/moisture out of it. Really, go to town.
In a large bowl, mix together the flours, baking powder and baking soda, and gradually add it to the olive oil mixture in the kitchen mixer (turn it to a low speed so the flour doesn't blow up in your face) and keep adding until all the flour has been incorporated. Add the vinegar, vanilla bean paste and wrung out zucchini, and mix on low until just combined. Allow the batter to sit for a minute or so - it should loosen and become a pourable consistency. Scrape the bottom to ensure there isn't any stagnant batter, and mix it through if there is.
Pour the batter into the greased and lined springform tin, and place it into the oven for 25-30 minutes.