Cook the ground beef meatballs to your liking, either in a pan or in the air fryer.
Heat up 1 tablespoon of olive oil in a pot over medium heat. Add the chopped yellow onion a few pinches of salt and pepper. Cook while stirring occasionally until they start to caramelize a bit. (about 6 to 8 minutes)
Add the minced garlic cloves, 2 tablespoons of tomato paste, 1 tablespoon Italian seasoning, then sprinkle some salt and pepper. Cook, stirring frequently for a whole minute.
Add a couple splashes of chicken broth, enough to scrape the bitts at the bottom of the pot, then add the rest of the broth, the crushed tomatoes, the uncooked pasta, and the cooked meatballs with some drizzles of salt and pepper.
Mix everything, then let it simmer over medium-high heat. Reduce the heat, then simmer covered for about 12 to 15 minutes (your pasta should be cooked)
Add in the baby spinach and heavy cream and stir until the spinach wilts.
Check if it needs additional salt or pepper then garnish with shaved Parmesan and chopped parsley. Enjoy!