In a large pot over medium heat, add the ground beef and onion. Cook 1-2 minutes or until browned, breaking into pieces. Drain the excess liquid.
Add the pasta, marinara sauce, garlic, salt, pepper, and water (or broth) to the pot. Stir to combine.
Increase the heat to medium-high, bringing the mixture to a boil. Cover, and simmer 11-13 minutes or until the pasta is al dente.
Add the ricotta and Mozzarella. Stir to combine.
Serve warm topped with Parmesan cheese, if desired!
