Preheat oven to 375°F (190°C)

Bring a large pot of salted water to a boil and cook pasta until al dente

Drain pasta and set aside

Heat olive oil in a large skillet over medium heat

Add crumbled Italian sausage and cook until browned

Stir in chopped onion and cook until softened

Add minced garlic and cook briefly until fragrant

Pour in marinara sauce and heavy cream

Season with Italian seasoning, salt, and pepper

Stir until the sauce becomes creamy and well combined

Add cooked pasta to the sauce and mix thoroughly

Transfer the mixture to a baking dish

Sprinkle mozzarella and Parmesan cheese evenly over the top

Bake until cheese melts and becomes bubbly

Garnish with chopped fresh basil before serving