Preheat the air fryer to 375°F (190°C) for 3–5 minutes. A hot basket helps build that crust.
Lightly oil the basket or tray to reduce sticking.
Form the patties. Divide the beef into 4 equal portions (about 4 ounces each). Gently shape into patties about 4 inches wide and 3/4 inch thick. Don’t overwork the meat.
Season simply and generously. Sprinkle both sides with salt and pepper.
Add a pinch of garlic and onion powder if you like. For extra depth, mix 1–2 teaspoons Worcestershire into the meat before shaping.
Make a slight dimple. Press your thumb into the center of each patty to create a shallow indentation. This helps them cook flat rather than puff up.
Air fry the first side. Place patties in a single layer, not touching.
Cook for 6–7 minutes.
Flip and finish. Turn the patties and cook another 4–6 minutes, depending on thickness and desired doneness. Add cheese in the last minute to melt.
Check doneness. For safety, ground beef should reach 160°F (71°C) internal temperature. Use an instant-read thermometer for accuracy.
Toast the buns. While the patties rest 2–3 minutes, pop buns (cut side up) into the air fryer at 350°F (175°C) for 1–2 minutes.
Brush with butter first if you want extra richness.
Assemble and serve. Layer sauce, patty, cheese, and toppings. Keep it classic or pile it high—your call.