Make jelly according to packet in a large mixing bowl. Transfer 2/3 of the warm jelly to trifle dish and add raspberries. Refrigerate the trifle dish uncovered for 1.5 hours. Set aside remaining jelly in the mixing bowl at room temperature.
After 1.5 hours, remove trifle dish from fridge, and put the remaining 1/3 jelly mixing bowl into the fridge to partially set for 30-60 minutes.
Spread the Dairy Farmers custard evenly onto the jelly in trifle dish.
After the remaining jelly mixture is partially set, spoon onto the top of the custard and smooth the surface.
Sprinkle sponge roll crumbs or slices over the top.
In a large bowl, whip thickened cream with vanilla essence and sugar until it thickens and forms stiff peaks. Spoon it over the sponge roll layer. Refrigerate for an additional 3 hours to allow flavours to meld.
Top with raspberry syrup, berries or icing sugar as desired. Enjoy your simple and delicious trifle!