Cook Pasta:
Bring a large pot of salted water to a boil. Cook pasta until al dente. Reserve ½ cup pasta water, then drain.
Cook Sausage:
Heat olive oil in a skillet. Add sausage, cook until browned and fully cooked. Remove and set aside.
Sauté Aromatics:
In the same skillet, sauté onion, garlic, and red bell pepper until softened.
Build the Sauce:
Stir in tomato paste, crushed tomatoes, Italian seasoning, and red pepper flakes. Simmer for 10 minutes.
Combine Everything:
Return sausage to the skillet. Add cream (if using), then stir in pasta. Toss to coat, adding reserved pasta water if needed.
Serve:
Garnish with basil or parsley and top with Parmesan cheese. Serve hot.