Bring a large pan of salted water to a rolling boil. Cook the pasta until al dente and drain, reserving a cup of the cooking water
Meanwhile place a wide pan over a medium heat with a little oil. Add the shallots and stir until starting to soften. Stir in the chilli flakes, garlic and courgettes. Cook until the courgettes are just starting to soften
Stir in the mascarpone, pasta and a splash of pasta water. Adjust seasoning and add lemon juice and Parmesan to taste
Stir in the basil and check again if it needs more pasta water to keep it silky
