Prep the asparagus. Rinse and pat dry. Snap or cut off the woody ends—bend near the base and let it naturally break, or trim about 1–2 inches.
Season the spears. Toss asparagus with olive oil, salt, pepper, garlic powder, and smoked paprika. Coat lightly so the bacon can still crisp.
Bundle and wrap. Make bundles of 3–5 spears, depending on thickness. Wrap each bundle with one slice of bacon, starting at the tip end and spiraling down, slightly overlapping as you go. Tuck the end underneath to help it stay put.
Preheat the air fryer to 390–400°F (200–205°C). A hot basket helps the bacon render quickly and crisp.
Arrange in the basket. Place bundles seam side down in a single layer with a little space between them. Work in batches if needed.
Air fry for 8–12 minutes. Start checking at 8 minutes. Thin bacon usually finishes around 8–10 minutes; thick-cut may need 12–14. Flip once midway for even browning if your air fryer cooks unevenly.
Optional glaze. For a sweet-savory finish, brush with a thin layer of maple syrup or honey during the last 1–2 minutes. Cook just until sticky and caramelized.
Rest and serve. Let bundles sit for 2–3 minutes so the bacon sets. Squeeze lemon over the top and serve warm.