What? I have no idea how one can pre-write essays for a humanity subject...
I do business studies and PDHPE (i dont really consider this a humanity but whatever) and I have NEVER written an essay in advance...
However, I did do that for english coz there's less variations in what they could ask you. For example, for journeys they pretty much just ask you what you learnt, the challenges, how the characters grew, detours, bla bla bla so it's easy to manipulate a pre-written essay.
But for something like business studies, there's no way you can pre-write an essay. The last 2 sections consist of a business report and an essay. These 2 extendeds can ask you about ANY of the 5 topics you have studied whilst linking 2 or 3 topics together. So they might ask you how marketing, employment relations and globalisation work together to do whatever...
The only thing I would recommend is just memorising the content and understanding it. If you're half decent in writing essays, the knowledge you have of the content in the syllabus will flow right out when trying to answer the question. There's really no need for you to pre-write essays for humanities (not that you can anyway).