Stir the sauce powder, sugar and 6 tablespoons of milk until smooth. Boil up the rest of the milk. Add the pudding powder while stirring continuously, bring to the boil and refrigerate. Wash raisins, dab dry and soak in rum.
Wash and peel the quinces, cut the flesh from the core. Bring apple juice to the boil, add lemon juice and quinces and cook for about 20 minutes until soft. Puree finely with a hand blender. Cut the brioche into slices about 3 cm thick.
In a greased casserole dish alternately layer quince puree, brioche and rum raisins. Repeat the process and finish with quince jam and raisins. Bake in a preheated oven (electric range: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 20 minutes.
Serve with the vanilla sauce.