Preheat oven to 350 degrees F (175 degrees C).
Cook ground beef in a large skillet over medium heat until meat is crumbly and no longer pink, about 5 minutes; drain and discard grease.
Stir refried beans, diced tomatoes with green chilies, salsa, and taco seasoning mix into ground beef.
Layer beef mixture into a 9x13-inch baking dish; top with tortilla chips and sprinkle with Cheddar cheese.
Bake in the preheated oven until cheese is melted and bubbly, about 30 minutes.
Remove casserole from oven and top with sour cream, green onions, and black olives.
Serve with optional toppings as desired.
