Step 1: Heat olive oil in a large skillet or Dutch oven over medium-high heat. Add the Italian sausage (casings removed) and break it up with a spoon. Cook until browned and no longer pink, about 6-8 minutes. Drain any excess grease, leaving a small amount in the pan.
Step 2: Reduce heat to medium. Add the diced onion to the skillet with the sausage and cook until softened, about 5 minutes. Stir in the minced garlic and cook for another minute until fragrant.
Step 3: Pour in the crushed tomatoes, chicken broth, and dried Italian seasoning. Bring the mixture to a simmer, then reduce the heat to low, cover, and let it cook for about 10-15 minutes, allowing the flavors to meld.
Step 4: While the sauce simmers, cook your pasta according to package directions in a separate large pot of salted boiling water until al dente. Reserve about 1 cup of pasta water before draining.
Step 5: Stir the heavy cream and grated Parmesan cheese into the sausage and tomato sauce. Cook for 2-3 minutes, stirring constantly, until the sauce thickens slightly and is heated through. Taste and adjust seasonings with salt and black pepper as needed.
Step 6: Add the cooked, drained pasta to the creamy sauce. Toss to coat thoroughly. If the sauce seems too thick, add a splash or two of the reserved pasta water until it reaches your desired consistency.
Step 7: Serve immediately, garnished with fresh basil or parsley and extra grated Parmesan cheese.