Combine the ground turkey, breadcrumbs, egg, Italian seasoning, minced garlic, and Parmesan cheese in a mixing bowl. Mix gently until evenly blended, then roll the mixture into small meatballs about one inch across.
Place the meatballs in the slow cooker. Add the chicken broth, diced tomatoes, carrots, celery, and zucchini.
Cover and cook on low until the meatballs are cooked through and the vegetables have softened.
Stir in the white beans, pasta, and spinach. Continue cooking on high until the pasta reaches a tender texture.
Taste and adjust with salt and black pepper. Ladle into bowls and top each serving with a few fresh basil leaves.