First whisk the eggs, vanilla essence and 50 grams of the caster sugar together in a large heatproof bowl.
Pour the milk and cream into a heavy-bottomed pan and slowly bring to a simmer then remove from the heat.
Slowly pour the milk and cream onto the egg mixture whisking continuously then set aside.
Butter the hot cross bun slices, then layer into an ovenproof dish. Pour the egg custard mix over the layered hot cross buns and leave to stand for thirty minutes.
Whilst the pudding is soaking up the egg mix preheat your oven to 350 F / 180 C / Gas Mark 4.
Sprinkle with the remaining sugar, cover the pudding with foil and place the whole dish into a large deep baking tray. Pour in enough water to the tray to come a third of the way up the pudding dish, this is a simple bain-marie and will help prevent the pudding overcooking.
Carefully place the bain-marie into the oven and bake for thirty to thirty-five minutes, or until the egg custard mix has set. Remove the foil for the final five minutes of cooking to brown the top.
Serve the pudding dusted with icing sugar and some cream.