Preheat and Prepare
Preheat your oven to 375°F (190°C). Lightly grease a 9×13 inch baking dish or similar casserole dish. Set aside while you prepare the meatloaf mixture.

Mix the Meatloaf Base
In a large mixing bowl, combine the ground beef, egg, milk, crushed Doritos, onion, garlic powder, chili powder, salt, pepper, and ½ cup of the shredded cheddar cheese. Mix everything together until well combined, but do not overwork the meat.

Form the Base
Press the meat mixture into the bottom of your prepared baking dish, creating an even layer. This forms the meatloaf portion of the casserole and will cook through while staying juicy and tender.

Prepare the Cheese Sauce
In a separate bowl, mix the condensed cheese soup (or nacho cheese sauce) with the sour cream. Stir until smooth. You can also add a few tablespoons of milk if the mixture seems too thick. This will become the creamy layer that melts into the meat while baking.

Layer the Cheese Sauce
Spread the cheese sauce evenly over the meatloaf layer. Use a spatula or the back of a spoon to distribute it, covering every inch for consistent flavor. This layer adds moisture and richness while preventing the meat from drying out.

Add More Cheese and Doritos
Top the cheese layer with the remaining shredded cheddar cheese, then sprinkle a generous handful of crushed Doritos over the top. This adds a golden, crunchy finish once baked.

Bake and Serve
Place the casserole in the oven and bake for 35–40 minutes, or until the meat is cooked through and the cheese is bubbly. Remove from the oven and let it rest for 5 minutes before slicing. Garnish with green onions or parsley if desired, and serve hot.