01 - Preheat oven to 400°F. Lightly grease a baking dish large enough to hold fillets in a single layer.
02 - Pat haddock fillets dry with paper towels and arrange in prepared dish. Brush tops with melted butter.
03 - In a medium bowl, combine breadcrumbs, parsley, lemon zest, Parmesan, salt, pepper, and olive oil. Mix until crumbs are evenly moistened.
04 - Spoon and gently press breadcrumb mixture onto tops of fillets, covering them evenly.
05 - Bake for 15 to 18 minutes, or until fish flakes easily with a fork and topping is golden brown.
06 - Serve hot, garnished with lemon wedges.