Place the chicken breasts in the slow cooker. Add the black beans, enchilada sauce, chicken broth, onion, garlic, chili powder, and cumin.
Stir the ingredients gently to combine, then cover and cook on low for 6 hours or until the chicken is tender and easy to shred.
Remove the chicken from the slow cooker and shred it with two forks. Return the shredded chicken to the pot.
Add the cream cheese cubes and stir until the cheese melts fully into the soup. Season with salt and pepper to taste.
Ladle the soup into bowls and top each serving with shredded cheddar cheese.