Add carrots, celery, yellow onion, diced tomatoes, tomato paste, garlic, bay leaves, Italian seasoning, red pepper flakes, bone broth, water, and beans to slow cooker. Stir to combine. Cover and cook on low for 6-8 hours, or high for 3-4 hours.
Before serving, add zucchini and pasta to slow cooker. Stir, cover, and cook on high for 20 minutes.
Just before serving, stir in frozen green beans and baby spinach. Cook on high for 5 minutes, or until spinach is wilted.
Divide soup into bowls and garnish with parmesan cheese. Enjoy!