Prep the pan: Lightly grease an air fryer-safe pan with oil or cooking spray. Preheat the air fryer to 350°F (175°C) for 3–5 minutes. Dry the potatoes: If your hash browns are wet, spread them on a clean towel and blot. Dry potatoes = crispier edges.
Build the base: In a bowl, toss hash browns with a pinch of salt, pepper, and a drizzle of oil. Press them evenly into the greased pan to form a compact layer, about 1 inch thick.
Par-crisp the base (optional but recommended): Air fry the hash brown layer at 350°F (175°C) for 8–10 minutes until starting to brown at the edges.
Whisk the custard: In a separate bowl, whisk eggs, milk, onion powder, garlic powder, smoked paprika, 1 teaspoon salt, and 1/2 teaspoon pepper.
Add mix-ins: Stir in 1 cup cheddar, green onions, bell pepper, and cooked bacon or sausage if using.
Pour and top: Pour the egg mixture evenly over the par-crisped hash browns. Sprinkle remaining 1/2 cup cheddar on top.
Air fry: Cook at 320°F (160°C) for 18–24 minutes, until the center is set and the top is golden. A toothpick should come out clean, or the center should jiggle just slightly but not look wet. Rest and serve: Let it cool 5 minutes so it sets. Slice and serve warm. Garnish with extra green onions or a dollop of sour cream if you like.
