Preheat your oven to 350°F. Lightly grease a 2-quart baking dish and set aside.
In a skillet over medium heat, cook the ground beef and onion until the beef is thoroughly browned and the onion is soft. Drain any excess grease from the skillet.
Mix in the chunky salsa, frozen corn, sour cream, chili powder, and salt with the beef and onion until well combined.
Spread half of the beef mixture into the bottom of the prepared baking dish. Sprinkle 1 cup of crushed tortilla chips over the beef, followed by 1/2 cup of grated cheddar cheese. Repeat with the remaining beef mixture, tortilla chips, and cheese.
Bake in the preheated oven for 20 minutes, or until the casserole is hot throughout and the cheese has melted.