Preheat the oven to 200C/400F/Gas 6.
To make the custard, place the fresh custard, milk and cream into a large bowl and mix well.
Melt the butter in a pan over a medium heat. Add the sugar and mixed spice and cook for two minutes.
Dip the brioche slices into the spiced butter to coat both sides, then arrange the slices in layers in an ovenproof dish.
Sprinkle with the sultanas and pour over the custard mixture and place in the oven to bake for 8-10 minutes.
To serve, spoon some of the pudding into a bowl and garnish with the orange slices.
