When your jelly is set, get ready for your jelly fluff. Add a tin of evaporated milk (I used light evaporated milk for this years trifle) to a mixer and put it on low for a few minutes. You can do this by hand, but the jelly fluff just won't be so fluffy.
Melt one jelly with a tablespoon of water in a jug in the microwave while the mixer is going and then add it to the evaporated milk in the mixer. Turn the mixer up and whizz until it is light and fluffy in the bowl. Leave it for around 10 minutes before pouring it onto your jelly. If it gets a little too thick, just whizz it for a minute.
Once the jelly fluff is set, it is simply a case of whipping up your cream, spreading it on the top and popping some decoration on the top.