Prep the crabs. If they aren’t cleaned, remove the face (just behind the eyes), lift the side flaps to pull out the gills, and trim the apron underneath.
Pat dry very well with paper towels. Dry crabs crisp better.
Preheat the air fryer to 400°F (200°C). A hot basket kick-starts crisping and prevents sticking.
Mix the coating. In a shallow dish, whisk flour, cornstarch, Old Bay, garlic powder, smoked paprika, salt, and pepper.
Beat the eggs. In another dish, whisk eggs with milk or buttermilk (if using). This creates a thin, sticky layer for the flour to grab.
Coat the crabs. Dip each crab into the egg, let excess drip, then dredge in the seasoned flour.
Press lightly so the coating adheres. Shake off extra.
Oil for crispness. Lightly spray both sides of each crab with cooking oil. Also spray the air fryer basket to prevent sticking.
Air fry in batches. Arrange crabs in a single layer, shell side down.
Cook at 400°F for 6–8 minutes, flip, spray again, and cook 4–6 minutes more. You want a deep golden color and an audible crunch.
Season and rest. Sprinkle with a pinch of salt while hot. Let them rest 1–2 minutes to set the crust.
Serve immediately. Add lemon wedges and your favorite sauce.
For a sandwich, tuck a crab into a toasted bun with lettuce, tomato, and tartar or remoulade.