Preheat the oven to 400°F (200°C)
Pat the cod fillets dry with paper towels
Place the cod on a lined or lightly greased baking sheet
Brush or drizzle the cod with olive oil or melted butter
Season with salt, black pepper, garlic powder, and paprika if desired
Add lemon slices or a squeeze of lemon juice
Bake for 10 to 12 minutes, depending on thickness
Check that the fish flakes easily with a fork and reaches 145°F (63°C) internally
Remove from the oven and serve immediately