In a medium bowl, combine 6 tablespoons of softened unsalted butter, 3 tablespoons of white miso paste, 1 tablespoon of brown sugar, 2 teaspoons of grated fresh ginger, 1-2 minced garlic cloves, and 2 tablespoons of thinly sliced green onions. Mash all the ingredients together until well blended and creamy.

Place salmon fillets skin-side down on a lined baking sheet or in an oven-safe skillet. Spread the miso butter mixture over each fillet.

Preheat oven to 375°F (190°C). Bake salmon for 12-15 minutes or until opaque and flakes easily. Broil for 1-2 minutes for a caramelized top.

If using an air fryer, preheat to 400°F (200°C), line with parchment, and cook salmon for 9-10 minutes.

Transfer cooked salmon to a serving platter. Drizzle with remaining miso butter and garnish with green onions and sesame seeds. Serve with steamed jasmine rice or sautéed vegetables.