Bring a large pot of salted water to a boil. Add the pasta and cook according to package instructions until al dente. Drain the pasta in a colander and set aside.
In a large skillet, heat the olive oil over medium heat. Add the chopped onion and sauté for about 3 minutes until softened.
Add the minced garlic to the skillet and cook for an additional minute, stirring frequently to prevent burning.
Pour in the crushed tomatoes and stir in the Italian seasoning. Allow the mixture to simmer for about 5 minutes, letting the flavors meld.
Reduce the heat to low, and slowly stir in the heavy cream. Cook for 2-3 minutes, allowing the sauce to warm through.
Season the sauce with salt and pepper to taste.
Add the cooked pasta to the skillet, tossing it to coat evenly with the creamy tomato sauce.
Remove from heat and stir in the grated Parmesan cheese until fully melted and combined.
Serve immediately, garnished with fresh basil leaves and additional grated Parmesan cheese, if desired.