Place the berries in an oven-safe casserole dish. Split the vanilla pod down the middle. Scrape out the seeds and add them to the dish along with the pod. Sprinkle the fruit with sugar and give everything a toss to combine.
Roast for 45 minutes to 1 hour, stirring once or twice during the cooking time. The berries will break down, releasing a sweet syrup much like a compote.
Remove the vanilla pod and serve the roasted summer berries as desired.