Saute minced onion in 1 tablespoon of olive oil. Make a foil sling, place it in the air fryer- this will make it easier to lift the meatloaf out of the pan later. You do not need to line the whole basket with foil.: As the onion hits the hot olive oil , you will hear a gentle sizzle and soon smell a sweet, savory aroma as the edges turn translucent. This process softens the sharp bite and releases sugars, which blend into the meat for a mellow, cohesive flavor. If the onion browns too fast it can develop bitter notes, so keep the heat moderate and stir often until soft and fragrant, about a few minutes. Avoid overcrowding the pan, which can steam the onion instead of sautéing it, leaving raw texture.
Use your hands to mix the ground beef, egg, bread crumbs, ketchup, mustard, seasoning salt, pepper, garlic powder, parsley, milk, and sauteed onion. Form this mixture into a loaf about 6 inches long, 4 inches wide, and 2 inches high.: When you form a simple foil sling, you create a clean way to lift the loaf, and you will notice less sticking and easier cleanup. The foil will warm quickly and reflect heat, helping the bottom brown without burning. Be careful not to cover the airflow vents of the air fryer , as obstructing circulation can lead to uneven cooking. If you skip the sling, use sturdy lifters designed for the basket to avoid dropping the loaf.
Place the meatloaf onto the foil sling. Bake the meatloaf for 15 minutes at 370 degrees. During this cooking time, make the glaze.: Working by hand is tactile and practical, letting you feel when the mixture is cohesive but not overworked; you will detect the mixture coming together as it holds shape without becoming dense. As you fold, the aromas of ground beef and onion meld with the tang of ketchup and Dijon mustard , creating a balanced scent. Overmixing will compact proteins and make the loaf tough, so stop once ingredients are evenly distributed. If the mixture feels too wet, add a touch more bread crumbs ; if it seems dry, a splash more milk will help.
In a small bowl, mix together the ketchup, brown sugar, mustard, and garlic powder. Pour the glaze over the top of the meatloaf. Return the meatloaf to the air fryer and bake for another 15 minutes or until a meat thermometer reaches 160 degrees.: Shape the loaf gently so the surface is smooth and compact, which helps even cooking and neat slicing later; you should feel a slightly firm but springy texture. The visual cue is a uniform exterior with no large cracks that could let juices escape. Press too hard and the loaf will become dense, press too little and it may crumble during cutting. Aim for an even thickness so the center reaches the correct temperature at the same time as the edges.
When the meatloaf is finished cooking, rest it on the counter for 5-10 minutes before cutting it with a sharp serrated knife.: Lowering the loaf onto the sling, you will notice the weight sits evenly and the foil supports lifting when done. This placement prevents direct contact with accessory pans and encourages hot air to crisp the exterior while keeping the interior moist. If the loaf is too close to the heating element it may overbrown on top, so center it in the basket. Use caution when handling the sling to avoid tearing it, which can make removal difficult.
Bake the meatloaf for 15 minutes at 370 degrees.: In the air fryer you will hear a light fan hum as hot air circulates, and the exterior will begin to take on color. The initial 15 minutes create a sealed crust that traps juices, so the interior remains tender. Watch the edges for a deepening tan as a sign of progress, and resist the urge to open the basket repeatedly, which releases heat and lengthens cook time. If the exterior browns too quickly, lower the temperature slightly to allow the center to catch up.
During this cooking time, make the glaze.: Mixing the glaze ingredients yields a glossy, fragrant sauce that will caramelize attractively. The brown sugar dissolves into the ketchup , and the Dijon mustard adds a bright backbone. Doing this while the loaf starts cooking ensures the glaze is ready when you need it, preserving timing and allowing the flavors to meld. If the glaze is too thin, a tiny pinch more brown sugar will thicken it, but avoid making it gritty with too much sugar.
In a small bowl, mix together the ketchup, brown sugar, mustard, and garlic powder.: As you whisk, the texture becomes smooth and the scent becomes a sweet tang with a hint of savory garlic powder . This combination will form the shiny finish the moment it warms on top of the loaf. Taste and adjust if your ketchup brand is very sweet or very tart, keeping the balance in mind. Using a bowl large enough to whisk vigorously avoids missed pockets of dry sugar.
Pour the glaze over the top of the meatloaf.: The glaze should adhere and begin to gloss over the surface, creating a barrier that will caramelize and add textural contrast. You will see a wet, ruby sheen that, after reheating, turns sticky and slightly browned. Be careful not to pool glaze at the base where it can drip and burn; spread it evenly with a spoon or brush for uniform coverage. If you over-glaze, the top can become overly sweet or form a thick crust that detracts from the tender interior.
Return the meatloaf to the air fryer and bake for another 15 minutes or until a meat thermometer reaches 160 degrees.: During this final stage you will notice gentle bubbling of the glaze and a deepening color. The internal temperature is the reliable cue for doneness, ensuring safety and juiciness. When the thermometer hits 160 degrees , the meat will be cooked through yet still moist if not overcooked. A common error is relying solely on time rather than temperature, which can leave the center underdone or make the loaf dry from overcooking.
When the meatloaf is finished cooking, rest it on the counter for 5 to 10 minutes before cutting it with a sharp serrated knife.: As it rests, juices redistribute and the loaf firms, which helps you get clean slices rather than a crumbly mess. You will notice the aroma mellow and the juices stay within the slice instead of running out. Cutting too soon will cause loss of moisture and messy presentation. Use a sharp serrated knife and let gravity and a gentle saw motion do the work for tidy portions.