1.Add pasta to a large pan of boiling well-salted water; boil, uncovered, until just tender. Reserve 1/2 cup (125ml) of the cooking water; drain pasta, return to pan.
2.In a medium frying pan, heat 1 tablespoon of the oil. Add prosciutto, in batches, in a single layer; cook until browned. Remove from pan. Reserve some prosciutto for garnish; crumble remaining prosciutto.
3.Add zucchini to same pan, cook, stirring, until softened but not coloured. Add the remaining oil with garlic and chilli; cook, stirring, until fragrant.
4.Toss zucchini mixture, including the oil, with hot pasta, crumbled prosciutto, parsley and enough of the reserved cooking water to moisten. Season to taste.
5.Top the pasta with parmesan and reserved prosciutto. Serve with lemon wedges, crusty bread and a rocket salad, if desired.