Bring a large saucepan of salted water to the boil over a high heat.
Add the spiral pasta and cook until al dente, about 9–11 minutes, reserving about 120 ml of the pasta water before draining.
Meanwhile, heat the olive oil in a large frying pan over a medium–high heat.
Add the Italian sausage meat and cook, breaking it up with a wooden spoon, until browned with no pink remaining, about 6–8 minutes.
Drain off any excess fat, leaving about 1 tbsp (15 ml) in the pan.
Reduce the heat to medium, add the chopped onion and cook until softened and translucent, about 5–7 minutes.
Stir in the minced garlic and cook for about 1 minute until fragrant.
Pour in the chopped tomatoes and chicken stock, stir well and bring to a gentle simmer.
Reduce the heat to low, cover and simmer for 10 minutes.
Uncover, stir in the double cream, grated Parmesan, salt and black pepper, and cook until the sauce is smooth and warmed through, about 2–3 minutes.
Add the drained pasta to the sauce and toss to coat, adding reserved pasta water as needed to loosen the sauce.
Stir through the chopped basil and serve immediately with extra Parmesan, if desired.