In a small bowl, combine the melted butter, olive oil, breadcrumbs, minced garlic, parsley, salt, and pepper. Mix until the breadcrumbs are evenly coated.
Pat the haddock fillets dry with paper towels. Place them in the air fryer basket in a single layer.
Spoon the breadcrumb mixture evenly over the fillets, gently pressing it down so it adheres.
Air fry at 400°F for 12 minutes, or until the fish flakes easily with a fork and the crust is golden brown.
Garnish with extra parsley and serve with lemon wedges if desired.