Place the chicken breasts in the bottom of your slow cooker and season with kosher salt, garlic powder, chili powder, and cumin.
Pour one, 10-ounce can of enchilada sauce over the top of the seasoned chicken.
Cover and cook the chicken on low for 4-5 hours or on high for 2-3 hours, or until it's fully cooked and shreds easily with a fork.
Once fully cooked, shred the chicken and mix it into the enchilada sauce in the slow cooker.
Preheat your oven to 350°F.
Wrap the corn tortillas in damp paper towels and microwave for 1 minute. This helps prevent them from cracking.
Pour half of the second can of enchilada sauce into the bottom of an extra-large casserole dish and spread it out into an even layer. Note: It might be challenging to find a baking dish large enough to fit all 14-16 assembled enchiladas. If you don't have an extra large dish and would like to bake all of the chicken enchiladas at the same time, you'll need to use two medium-sized casserole dishes. The half can of enchilada sauce can be divided between the two medium-sized dishes.
Assemble your enchiladas. Scoop ¼-cup of shredded chicken into the center of a tortilla and top it with 1-tablespoon of shredded cheese. Roll it tightly and place it in your prepared casserole dish, seam side down. Repeat this step until you've used up all of your chicken and tortillas.
Pour the remaining enchilada sauce over the assembled enchiladas, then sprinkle the rest of the shredded cheese on top.
Transfer the chicken enchiladas into your preheated oven and bake for 15 minutes, or until the cheese has melted and the enchilada sauce is bubbling.
Serve immediately and enjoy!