Begin by cooking your penne pasta according to package instructions until it's al dente. Before draining, reserve about 1 cup of the starchy pasta water.

In a large skillet over medium heat, pour in the olive oil and let it warm up. Sauté the diced onion and minced garlic for about 5 minutes, or until they turn fragrant and translucent.

Add the ground beef, breaking it apart with your spatula. Allow it to cook for about 7 minutes, seasoning with salt, pepper, and Italian seasoning, until nicely browned.

Lower the heat and gently stir in the heavy cream, gradually incorporating the reserved pasta water until you reach your desired sauce consistency. Stir in the grated Parmesan cheese until it melts into the sauce.

Take the cooked penne and add it to the skillet, tossing gently to coat every piece with the creamy sauce. Serve hot, garnished with additional Parmesan or parsley if desired.