Heat half the butter with the oil, then add the garlic and mussels. Pour in the wine, season, cover and cook over a high heat until the mussels open.
Drain the mussels, reserving the cooking liquid. Remove the mussels from their shells, discarding the shells and any that have not opened.
Heat the remaining butter in a pan and add the mussel juices and the cream. Cook gently to reduce to a thick creamy consistency then add the mussels and the parsley.
Cook the Ditaloni in boiling salted water until al dente, then drain and add to the sauce. Toss together over a low heat and serve.