Make 2 packets of jelly as per the pack. Pour them into the bowl. Add some fresh raspberries if you wish. Put it in the fridge to set for 1.5 hours or overnight.
Break the sponge into pieces and put it in a mixing bowl. Make up the remaining pack of jelly as per the pack, and pour it over the sponge. Add the sherry now if you wish. Smooth it over and put it in the fridge to set for 1.5 hours.
Slice some strawberries into pieces, keeping the strawberry shape. Once the jelly in the bowl is set. Scoop the trifle on top but leave a gap around the edge. Put the strawberry slices around the edge of the bowl. Add the remaining trifle and smooth down with a spoon. Pour on the cold custard and smooth with a spoon.
Whip the cream until it holds in the whisk, don't over whip. Spoon on top of the custard. Decorate with extra raspberries and strawberries.
