Prep the sprouts. Rinse, trim the ends, and remove any yellowed leaves.
Halve them lengthwise. For very large sprouts, quarter them so everything cooks evenly.
Dry them well. Moisture is the enemy of crisp. Pat the sprouts with a clean towel until dry.
Season. Toss sprouts with olive oil, salt, pepper, garlic powder, and red pepper flakes if using.
Start with about 1/2 teaspoon salt and 1/4 teaspoon pepper for a pound of sprouts; you can adjust after cooking.
Add bacon. Chop bacon into 1/2-inch pieces. Toss it right in with the seasoned sprouts so the bacon fat flavors everything as it cooks.
Preheat the air fryer. Set it to 380–390°F (193–199°C) for a few minutes. A hot basket helps the sprouts sear instead of steam.
Arrange in the basket. Spread the mixture in an even layer.
A little overlap is fine, but avoid a thick pile. If your air fryer is small, cook in two batches for best crisping.
Cook for 14–18 minutes. Shake the basket halfway through to redistribute and expose new edges. Keep an eye on the last few minutes to prevent over-browning.
You’re aiming for deep golden edges and tender centers.
Finish to taste. For brightness, drizzle with 1–2 teaspoons balsamic or a squeeze of lemon. For a sweet-savory note, add a touch of honey or maple while the sprouts are hot and toss to coat.
Serve. Transfer to a platter, sprinkle with freshly grated Parmesan if you like, and add a final pinch of salt to wake up the flavors.