Slow Cooker Vegetarian Minestrone

Name: Slow Cooker Vegetarian Minestrone
Ingredients: 6 cups vegetable broth; 1 (28 ounce) can crushed tomatoes; 1 (15 ounce) can kidney beans, drained; 1 large onion, chopped; 2 large carrots, diced; 2 ribs celery, diced; 1 cup green beans; 1 small zucchini, chopped; 3 cloves garlic, minced; 1 tablespoon minced fresh parsley; 1.5 teaspoons dried oregano; 1 teaspoon salt; 0.75 teaspoon dried thyme; 0.25 teaspoon freshly ground black pepper; 0.5 cup elbow macaroni; 4 cups chopped fresh spinach; 0.25 cup finely grated Parmesan cheese, or more to taste