Stir the cottage cheese, eggs, parmesan cheese and oregano in a medium bowl.
Cook the beef in a 10-inch skillet over medium-high heat until it's well browned, stirring often to break up the meat. Pour off any fat. Stir the tomato sauce, picante salsa, chili powder and corn in the skillet. Heat through.
Arrange 6 tortillas in the bottom and up the sides of a 3-quart shallow baking dish. Top with half of the beef mixture. Spoon the cottage cheese mixture over all. Top with the remaining tortillas and beef mixture.
Bake at 400°F for 30 minutes or it's until hot and bubbling. Sprinkle with the cheddar cheese. Let stand for 10 minutes
Sprinkle with cotija cheese, and serve with additional salsa or pico de gallo.