Follow the steps in order for the best result.
In a large skillet, sauté the chopped onion in the light Italian dressing over medium heat until they become tender-crisp.
Add the ground beef to the skillet. Cook over medium-high heat, breaking it apart and stirring frequently, until the beef is browned.
Stir in the can of tomato sauce and the can of diced tomatoes (undrained).
Bring the sauce to a boil, then reduce the heat to low. Simmer for 15 minutes, stirring occasionally, to allow the flavors to meld together.
While the sauce simmers, cook the spaghetti according to the package directions until al dente. Reserve about 1/2 cup of the pasta water before draining.
Remove the Bolognese sauce from the heat.
Incorporate the reduced-fat cream cheese into the sauce. Stir until the cream cheese is completely melted and the sauce is smooth and creamy.
Drain the cooked spaghetti and transfer it to a large serving bowl.
Pour the zesty Bolognese sauce over the spaghetti.
Sprinkle the grated Parmesan cheese over the top of the sauced spaghetti.
Serve immediately and enjoy!