Most trifle is not vegan due to the sponge layer (often made with dairy & eggs), as well as the cream and custard layers (dairy and sometimes eggs). It is very easy to make trifle vegan, though. Especially if you're planning on serving it at a party in this day and age where food intolerances or special diets run rampant, your guests may be very thankful to have a plant-based option!