don't bother remembering word for word, because if u forget something then you will stuff up. make sure u understand what you are actually writing about, remember key words and points, and don't stress out too much before the test.
It takes me around 3 hours to remember a 1600 word essay. I always read it outloud to myself like a speech.
Hint: Try to physically memorise the topic sentence (act it out if you must ) and it should flow out from there.