- With the rack in the middle position, preheat the oven to 180 °C (350 °F). Butter a 23 x 13-cm (9 x 5-inch) baking dish.
- In a bowl, combine milk, cream, eggs, sugar and vanilla. Set aside.
- Place chocolate croissant slices at the bottom of the baking dish, placing an apple slice between each. Drizzle with a little egg mixture. Continue layering with remaining ingredients. Let soak for about 10 minutes.
- Sprinkle with brown sugar and bake for about 40 minutes. Let cool. Serve warm or cold.