In a 4-quart Dutch oven cook garlic and onion in hot oil until tender. Add sweet pepper, zucchini, broth, and 2 cups water. Bring to boiling. Rinse and drain beans. Add drained beans and pasta; return to boil. Reduce heat. and simmer, covered, for 10 to 12 minutes or until pasta is tender, stirring occasionally.
Stir in tomatoes, spinach, and fresh basil (if using). Remove from heat. Season to taste with salt and ground black pepper.