Altered ingredient amounts.
I made some subs: i used only brown sugar, no caster. i used i tin of crushed pineapple and 120ml oil. added 2.5 tsp cinnamon and 1/4 tsp nutmeg, 3 tsp vanilla. omitted nuts and icing. I baked in two round cake tins for 40 minutes. The result was perfectly moist cake with terrific flavour, and less guilt! Suggestion: if you're using a box grater, grate the carrots on the 2nd largest holes (same ones you use to grate cheese). I made the mistake of grating on the next smaller size holes last time. The carrot shreds were too small and too many, and a lot of carrot juice was produced. All that extra liquid caused my "cake" to be more like a thin rubbery glob, even after cooking for over an hour. So make sure your carrot shreds are quite large, so you don't end up with all that unwanted carrot juice.