Bring a large pan of lightly salted water to the boil, then cook the pasta according to the packet instructions.
Meanwhile, heat the butter and olive oil in a large frying pan, then add the chilli, garlic, spring onions and courgettes. Cook over a medium-low heat for 10–15 minutes, or until softened, stirring often.
Reduce the heat and add the lemon zest. Cook gently for 3–4 minutes, add the soft cheese and mix thoroughly. Season to taste.
Drain the pasta and add to the courgette mixture. Stir in the parsley, mix well and serve immediately.