01 - Preheat oven to 375°F. Lightly grease a 9x13-inch baking dish.
02 - In a large skillet over medium heat, cook ground beef, breaking up with a spoon, until browned (about 5 minutes). Drain excess fat.
03 - Add diced onion to the beef and cook for 3 minutes, then stir in minced garlic and cook for 1 minute.
04 - Mix in chili powder, cumin, smoked paprika, salt, pepper, corn kernels, and black beans. Cook for 2 more minutes, then remove from heat.
05 - Spread 1/2 cup enchilada sauce on the bottom of the prepared baking dish. Layer 4 tortillas over the sauce, overlapping as necessary.
06 - Spoon half of the beef mixture over the tortillas. Top with 1/3 of the shredded cheeses.
07 - Pour 1/2 cup enchilada sauce over the beef layer.
08 - Place the remaining four tortillas on top. Spread the rest of the beef mixture over them, followed by another 1/3 of the cheeses.
09 - Pour the remaining enchilada sauce over the casserole and top with the remaining cheese.
10 - Cover with foil and bake for 25 minutes.
11 - Remove foil and bake an additional 10 minutes until cheese is bubbly and slightly golden.
12 - Let rest 10 minutes before slicing. Garnish with cilantro, tomatoes, jalapeños, and sour cream as desired.