Heat the oven: Set to 400°F (200°C).
Line a baking dish with parchment or lightly oil it to prevent sticking.
Prep the cod: Pat fillets dry with paper towels. Dry fish browns better and releases less water as it bakes.
Season generously: Sprinkle both sides with salt and black pepper. Add a light dusting of paprika if using.
Make the lemon-dill mixture: In a small bowl, combine 2 tablespoons olive oil, juice of 1 lemon, minced garlic, and half the chopped dill.
Whisk together. Taste and adjust salt if needed.
Assemble in the dish: Place cod in a single layer. Spoon the lemon-dill mixture over the top.
Dot with small pieces of butter for extra richness. Scatter capers if using. Lay thin lemon slices over the fillets.
Bake: Cook for 10–14 minutes, depending on thickness.
Cod is done when it flakes easily with a fork and looks opaque throughout. Aim for an internal temperature of 130–135°F (54–57°C) for moist, tender fish; it will rise a few degrees off heat.
Finish with herbs: Sprinkle the remaining dill over the hot fish. Add a final squeeze of lemon if you like it extra bright.
Serve: Spoon the pan juices over the fillets.
Pair with roasted potatoes, steamed green beans, asparagus, or a simple salad.