Plum and ginger trifle Author: Paul Johnson Serves: 4 Ingredients Ginger sponge: 225g butter 225g soft brown sugar 225g black treacle 2 eggs 350g plain flour 2 tsp ground ginger 1 tsp cinnamon pinch salt 300ml milk 2 tsp bicarbonate of soda Roast plums: 6 plums, halved and stoned 50g demerara sugar 50g honey Plum