Preheat the oven to 200°C (392°F).
Cube the aubergines, tomatoes, onion and celery, and place them in a large baking tray.
In a small bowl, dissolve the brown sugar into the vinegar, then pour the mixture over the chopped vegetables.
Drizzle over the olive oil, and scatter the capers, olives, and raisins on top.
Season with salt, give everything a good stir, and spread evenly in the tray.
Bake for 40–50 minutes, stirring halfway through, until the vegetables are fork-tender and caramelised.
Remove from the oven, let cool for about 20 minutes, and then stir through the torn basil leaves.
Serve at room temperature or chilled, ideally with crusty bread or as part of an antipasti spread.