01 - Preheat the oven to 400°F. Lightly grease a baking dish large enough to hold the fillets in a single layer.
02 - Pat the haddock fillets dry with paper towels and place them evenly in the prepared baking dish.
03 - In a small bowl, whisk together olive oil, lemon juice, lemon zest, minced garlic, sea salt, and black pepper until combined.
04 - Drizzle the olive oil mixture evenly over the haddock fillets.
05 - Sprinkle drained capers and chopped fresh parsley over the fish.
06 - Bake for 16 to 18 minutes until the fish flakes easily with a fork and is opaque throughout.
07 - Serve immediately, garnished with additional parsley and lemon slices if desired.