Preheat the oven to 180 degrees Celsius. Grease and line a 24cm spring form cake tin (or two, if you’re doubling).
Grate the carrot (I like to roughly chop over my grated carrots for finer carrot bits) and place it in a colander or sieve over the sink. Sprinkle over the salt, and use your hands to rub it in. This will start drawing the moisture out of the carrots so you can wring as much liquid out as possible. Leave them to sit while you work on the rest of the cake.
In a large mixing bowl, combine all the dry ingredients. In another, crack out your eggs and lightly whisk them. I like to crack my eggs into a small bowl first to check they aren’t bad, before adding them in with the rest of the bunch.
In ONE FINAL BOWL, mix the milk and the apple cider vinegar to make a buttermilk.
While this is happening, keep wringing out your carrots. A considerable amount of liquid should be expelled, and they should almost look like handful of cooked shredded carrots. If you don’t wring them enough, the cake will be soggy, but also too carroty. It’s a thing. Once you really can’t wring any more liquid out of the carrots, set them aside.
Add the whisked eggs, oil and buttermilk to the dry ingredients, and stir thoroughly to incorporate. Add the carrots and stir again until they are evenly distributed.
If you’re adding walnuts, do so now. Keep in mind that they make the cake harder to slice, so make sure you chop them relatively finely.
Place the cake in the oven for 40-45 minutes, or until a skewer comes out clean.
Allow the cake(s) to cool COMPLETELY before moving on to icing them.