Heat up the olive oil, then stir in the eggplant, making sure it all gets coated in oil. Let cook, stirring occasionally, for about ten minutes.
Add the garlic and chilis to the pan and cook, stirring, for a couple more minutes.
Add the tomatoes to the pan, then crush and break them up with your wooden spoon. Pour in the balsamic vinegar, then add the sugar and season generously. Simmer for about 15 minutes or until the eggplant is nice and soft.
Stir in most of the basil at the end of the cooking time.
Meanwhile, boil the pasta according to the packet instructions (until al dente is best), then drain, reserving some of the water.
Add the pasta to the sauce and toss until well coated. Add enough of the reserved cooking water to make the dish nice and smooth and ‘saucy’, then rip the mozzarella into the pan and stir again briefly.
Serve out into bowls immediately, topping with grated parmesan and the remaining fresh basil.