Pat the halloumi cubes dry with paper towels. Removing surface moisture helps the coating stick and the cheese crisp instead of steam.
Put the cubes in a mixing bowl and toss with the olive oil until every piece is lightly coated.
Sprinkle the cornstarch, garlic powder, smoked paprika, and black pepper over the cubes. Toss again until each piece has a thin, even coating.
Preheat the air fryer to 200 C / 400 F for 3 minutes.
Arrange the cubes in a single layer in the basket, leaving space between each piece. Work in two batches if your basket is smaller than 20 cm / 8-inch, so the cubes don't touch.
Air fry for 8 minutes, shaking the basket at the 4-minute mark, until the cubes are golden and crisp on the outside and soft in the middle.
Transfer the bites to a plate. Drizzle with hot honey and squeeze a lemon wedge over the top.
Scatter with parsley or chili flakes and serve right away while warm.