Place the chicken breasts at the bottom of the crockpot. Season with ground cumin, chili powder, garlic powder, salt, and pepper.
Pour half of the enchilada sauce over the chicken, ensuring it is well covered.
Layer 2 tortillas over the sauce. You can tear them into smaller pieces to cover more surface area.
Add half of the black beans, half of the corn, and a third of the shredded cheese on top of the tortillas.
Repeat the layers with the remaining ingredients: pour the rest of the enchilada sauce, add another 2 tortillas, the rest of the black beans, corn, and finally the remaining cheese on top.
Cover the crockpot and cook on low for about 6 hours or until the chicken is fully cooked and tender.
Before serving, shred the chicken right in the crockpot using two forks and mix everything together.
Serve hot, garnished with fresh cilantro and a dollop of sour cream, if desired.