01 - Set the air fryer to 375°F and allow it to preheat while you prepare the sprouts.
02 - In a large mixing bowl, toss the trimmed and halved Brussels sprouts with olive oil, garlic powder, smoked paprika, kosher salt, and black pepper until every piece is evenly coated.
03 - Place the seasoned Brussels sprouts in a single layer inside the air fryer basket, ensuring space between each piece for proper air circulation and even crisping.
04 - Cook for 12 to 15 minutes, shaking the basket vigorously halfway through, until the outer leaves are deeply golden and the edges are satisfyingly crisp.
05 - Transfer the hot sprouts to a serving bowl. If desired, sprinkle with grated Parmesan cheese and toss gently to melt it into the crevices. Drizzle with fresh lemon juice just before serving. Serve immediately while hot and crisp.