Bring 3-4 l salted water (1 teaspoon salt per litre) to the boil. Peel onion and garlic, dice finely. Peel, wash and chop the sweet potatoes. Squeeze the salsicce out of the skin.
Heat the oil in a pan. Brown the sausage meat in it and take it out. Fry the sweet potatoes in the frying fat for about 5 minutes. Fry onion and garlic for 2-3 minutes. Deglaze with tomatoes, bring to the boil. Season with salt, pepper and 1 pinch of sugar.
Simmer for about 10 minutes.
Cook the pasta in boiling salted water according to the instructions on the packet. Wash basil, shake dry, pluck leaves and chop finely. Stir sausage meat and 3⁄4 cream cheese into the sweet potato and tomato sauce, season to taste.
Drain the pasta, put it back into the pot and mix with the sauce. Crumble cream cheese over it.