Set slow cooker to High. Add chicken breasts and chicken broth and cook until chicken can be shredded with a fork, 3 to 4 hours.
Preheat oven to 350 degrees F (175 degrees C).
Mix cream of chicken soup, Cheddar cheese, salsa, green chiles, tortillas, garlic powder, chili powder, onion powder, and cumin together in a bowl. Shred chicken and add to the bowl. Pour into a casserole dish and cover with aluminum foil.
Bake in the preheated oven for 20 minutes; take off aluminum foil and bake until top is crispy, about 10 minutes more.