Cook the pasta according to directions. Before the water starts to boil, add about a tablespoon of salt and olive oil into the water. Stir the pasta to prevent sticking and drain when ready.
In a large sauté pan or skillet, heat olive oil over medium heat. Once heated, add the onion and garlic and cook until softened.
Ball or break apart the Italian sausage (make sure the casings are removed) and add to the pan. Cook for 5 minutes until the sausage is no longer pink.
Add the diced roasted tomatoes, tomato sauce, whipping cream, dried sage, red chili flakes, garlic powder (optional), and salt and pepper to taste. Stir to combine. Simmer covered over medium-low heat for 12 minutes.
Uncover the pan and add the ¾ cup of the parmesan cheese. Simmer uncovered for another 3 minutes until the sauce slightly thickens. Toss the cooked pasta with the sauce and serve with the remaining parmesan cheese. Enjoy!