Gather the ingredients. Preheat the oven to 350 degrees F (175 degrees C). Coat a casserole dish with cooking spray.

Heat olive oil in a large skillet over medium heat. Cook and stir onion in hot oil until translucent, 3 to 5 minutes. Add beef and increase heat to medium-high. Cook and stir until beef is browned and crumbly, 5 to 7 minutes. Drain and discard grease.

Mix together refried beans and burrito seasoning in a large bowl; add to beef mixture in the skillet and stir until well combined.

Mix together condensed soup and sour cream in a medium bowl.

Place a layer of tortilla chips into the prepared casserole dish to just cover the bottom, followed by 1/2 of the meat mixture, 1/2 of the soup mixture, 1 cup cheese, and 1/2 of the salsa. Repeat layers once more, then top with remaining cheese.

Bake in the preheated oven, uncovered, until hot and bubbly, 20 to 30 minutes.