Heat a large skillet over medium heat. Add the beef and cook, breaking up any big chunks, until no pink remains, about 5-6 minutes. Season with salt, pepper, and garlic powder. Set aside.
Divide the lettuce among four bowls and top with beef, cheese, pickles, tomatoes, and onions. Drizzle with big mac sauce.
For the croutons:
Slice some sesame seeds buns into cubes. Drizzle with a few teaspoons olive oil and sprinkle with salt and garlic powder. Air fry for 3 minutes, toss, and fry another 1-2 minutes, or until golden brown and toasted.
Notes
Croutons can also be toasted on a baking sheet in the broiler