Bring a large pot of salted water to a boil and cook the pasta according to package instructions. Before draining, reserve ½ cup of pasta water.
Heat a drizzle of olive oil in a large pan over medium heat. Add the Italian sausage and break it into smaller pieces as it cooks. Cook until browned and fully cooked through.
Push the sausage to one side of the pan and add the minced garlic. Cook for about 30 seconds, stirring until fragrant.
Stir in the tomato paste and cook for 1–2 minutes, allowing it to darken slightly to develop deeper flavor.
Pour in the tomato sauce and add the salt, Italian seasoning, and chili flakes. Stir well to combine.
Add the heavy cream and mix until the sauce becomes smooth and creamy.
Add the cooked pasta to the pan along with ½ cup reserved pasta water. Toss everything together until the sauce coats the pasta evenly.
Top with grated Parmesan cheese if desired and serve warm.