01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper or lightly grease it.
02 - In a small bowl, whisk together the miso paste, maple syrup, soy sauce, rice vinegar, and sesame oil until smooth.
03 - Pat the cod fillets dry with paper towels and arrange them on the prepared baking sheet.
04 - Brush each fillet generously with the miso-maple glaze, coating the tops and sides.
05 - Bake for 12–15 minutes, or until the cod is opaque and flakes easily with a fork.
06 - For extra caramelization, broil the cod on high for 1–2 minutes at the end, watching carefully to avoid burning.
07 - Transfer to plates, sprinkle with sesame seeds and spring onions, and serve with lemon wedges.