In a medium mixing bowl, gently combine the ground beef, salt, black pepper, garlic powder, and onion powder. Be careful not to overmix, as this can make the burgers tough.

Divide the seasoned ground beef into 4 equal portions. Form each portion into a patty, about 3/4-inch thick and slightly wider than your hamburger buns, as they will shrink during cooking. Press a shallow indentation into the center of each patty; this helps prevent the burger from bulging in the middle.

Preheat your air fryer to 375°F (190°C) for 3-5 minutes, if your model requires preheating.

Place 2 hamburger patties in the air fryer basket, ensuring they are in a single layer and not overcrowded. (You will likely need to cook in batches depending on the size of your air fryer).

Cook for 8 minutes, then carefully flip the patties. Continue cooking for another 4-7 minutes, or until the burgers reach your desired doneness (160°F/71°C internal temperature for well-done). For medium-rare, aim for 12-14 minutes total; for medium, 14-16 minutes; for medium-well, 16-18 minutes.

If adding cheese, place a slice on each patty during the last 1-2 minutes of cooking, allowing it to melt. Remove the cooked patties from the air fryer and set aside. Repeat with any remaining patties.

For toasted buns, you can place the split hamburger buns in the air fryer basket for 1-2 minutes at 350°F (175°C) until lightly golden.

Assemble your burgers: place a patty on the bottom half of each bun, add your desired toppings (lettuce, tomato, onion, pickles), and condiments (ketchup, mustard, mayonnaise). Top with the other half of the bun and serve immediately.