This makes a large trifle - enough for a 3 litre dish - use clear serving dishes so you can see the lovely layers! Adjust according to your needs. It can be modified for individual servings as well. It's best to partially prepare 1 to 2 days in advance. Letting the sponge soak up the sherry before serving, it makes a big difference and the trifle will be better for it.
You can opt for fresh fruit - but then omit caster sugar.