In a large pot over medium heat, add the olive oil and sausage. Cook until browned, about 5-7 minutes. Break it apart with a spoon as it cooks.
When the sausage is browned, add chopped onions and minced garlic. Sauté until onions become translucent.
Stir in the canned tomatoes and vegetable broth. Bring to a gentle boil.
Once boiling, add the pasta to the pot. Cook according to the package instructions until al dente.
Stir in the spinach and let it wilt for about 2 minutes.
In a bowl, mix the ricotta cheese with a pinch of salt and pepper. Serve the soup in bowls and add a dollop of ricotta on top.
Finish with freshly grated Parmesan cheese and a sprinkle of fresh basil or parsley if desired. Serve hot and enjoy!