01 - Set the oven to 375°F.
02 - Cook ground beef in a large skillet over medium heat, breaking it up with a spoon until browned, about 5 minutes. Drain excess fat if necessary.
03 - Add chopped onion and cook until softened, approximately 3 minutes. Stir in garlic, cumin, chili powder, smoked paprika, salt, and black pepper and cook for 1 minute until fragrant.
04 - Incorporate black beans and corn if using, and cook together for 2 minutes. Remove skillet from heat.
05 - Spread 1/2 cup enchilada sauce evenly over the bottom of a 9x13-inch baking dish.
06 - Place one-third of the tortillas over the sauce, overlapping slightly.
07 - Top tortillas with half of the beef mixture, then sprinkle 2/3 cup of shredded cheese over it.
08 - Drizzle 1/2 cup of enchilada sauce over the cheese layer.
09 - Add another layer of tortillas, remaining beef mixture, 2/3 cup cheese, and 1/2 cup sauce.
10 - Place the last tortillas layer, remaining sauce, and the remaining shredded cheese on top.
11 - Cover the dish with foil and bake for 20 minutes. Then remove foil and bake an additional 10 to 15 minutes until the cheese is bubbly and golden.
12 - Allow the casserole to rest for 10 minutes before slicing. Garnish with green onions, cilantro, sour cream, and jalapeños as desired.