01 - Preheat the oven to 400°F. Lightly grease a baking dish large enough to hold the fillets in a single layer.
02 - Pat haddock fillets dry with paper towels. Arrange in the baking dish and season lightly with salt and pepper.
03 - In a bowl, combine melted butter, breadcrumbs, parsley, lemon zest, salt, and black pepper. Stir until crumbs are evenly coated.
04 - Spread breadcrumb mixture evenly over haddock fillets, pressing gently to adhere.
05 - Bake for 18 to 20 minutes until fish flakes easily with a fork and the topping is golden brown.
06 - Serve immediately with lemon wedges on the side.