Place the steak pieces in a bowl and toss them with olive oil until evenly coated.
In a small bowl, mix the brown sugar, salt, black pepper, chili powder, garlic powder, and onion powder.
Sprinkle the seasoning mixture over the steak bites and toss well so the pieces are evenly coated.
Preheat the air fryer to 400°F (200°C) for about 5 minutes.
Arrange the seasoned steak bites in the air fryer basket in a single layer.
Cook for 4–6 minutes, shaking the basket halfway through, until the steak reaches your preferred doneness.
While the steak cooks, melt the butter and mix it with garlic powder, red pepper flakes, and parsley flakes.
Transfer the cooked steak bites to a bowl and toss them with the garlic butter mixture. This step finishes the delicious air fryer steak bites with rich flavor.
Serve immediately while hot.