In a large pot, heat the olive oil over medium heat. Add the chopped onion and sauté for about 3-4 minutes until it becomes translucent. Stir in the minced garlic and cook for an additional 1 minute.
Add the vegetable broth and diced tomatoes (with their juice) to the pot. Stir in the Italian seasoning, salt, and pepper. Bring to a gentle boil, then reduce to a simmer.
Gently add the ravioli to the simmering broth and cook according to package directions, typically about 4-6 minutes.
Lower the heat and pour in the heavy cream, stirring to combine. Add the chopped spinach and cook for an additional 2-3 minutes.
Ladle the soup into bowls and garnish with fresh basil and Parmesan cheese before serving.
