2) Slice the brioche loaf into 6 (2.5-cm) thick pieces. Lay half the brioche slices flat in a 23 by 36 by 5-cm oval baking dish. Spread the sultanas on top of the brioche slices, and place the remaining slices on top. Make sure that the sultanas are between the layers of brioche or they will burn while baking.
3) Pour the egg mixture over the bread and allow to soak for 15 minutes, pressing down gently. Bake for 55 to 60 minutes or until the pudding puffs up and the custard is set. Remove from the oven and cool slightly before serving with maple syrup.