In a food processor blend together the basil, spinach, Parmesan, broth, onion, and garlic until smooth.
Add the mixture to a large skillet, along with the cream, over medium heat. Cook while stirring until the mixture is heated through and thickens, 3 to 4 minutes. Toss in the cooked pasta and stir to combine.
Mix in the diced tomatoes, mozzarella balls, salt, and pepper. Top with extra Parmesan (if using) and serve warm.