Preheat oven to 425 degrees F.
Mix the miso paste, maple syrup, vinegar, soy sauce and sesame oil together in a bowl until smooth. If needed, add a small amount of water.
Place the salmon fillets on a baking sheet lined with aluminum foil. Brush the glaze on top of the salmon.
Place the baking sheet on the top rack in the oven and cook 8-10 minutes until salmon is just cooked through.
Turn the broiler on high and broil the salmon for another 2 minutes until it is browned in spots.
Garnish salmon with sesame seeds and scallions, if desired.
