Preheat the oven to 350°F (175°C) and grease a 9x13 inch baking dish with cooking oil or non-stick spray.

Heat a large skillet over medium-high heat, add ground beef and cook, breaking into small pieces, for 5 to 7 minutes until browned and no pink remains.

Drain excess grease, leaving about 1 tablespoon in the skillet, then add diced onion and cook for 2 to 3 minutes until softened and translucent.

Sprinkle cumin, garlic powder, salt, and black pepper over the beef and onion mixture, stir to coat, and toast the spices for 30 seconds.

Remove the skillet from heat and stir in sour cream and 1 cup of shredded cheddar cheese until well combined.

Pour Old El Paso enchilada sauce and tomato sauce into a shallow dish and stir until smooth, then briefly dip each corn tortilla or brush flour tortillas with sauce to soften.

Place a softened tortilla on a clean surface, spoon 3 to 4 tablespoons of the beef filling down the center, roll tightly, and place seam-side down in the prepared baking dish. Repeat with remaining tortillas and filling.

Pour any remaining sauce evenly over the rolled enchiladas and sprinkle with the remaining 1 cup of shredded cheddar cheese.

Cover the baking dish with aluminum foil and bake for 20 minutes, then remove the foil and bake for another 5 to 8 minutes until the cheese is melted, bubbly, and edges begin to brown.

Let the enchiladas rest for 5 minutes after baking before serving to allow the filling to set.