Begin by rinsing sushi rice under cold water until the water runs clear. Combine the rinsed rice with water, bring to a boil, then reduce heat and cover. Cook for about 20 minutes until tender, then let sit covered for another 10 minutes.

Prepare the vinegar mixture by whisking rice vinegar, sugar, and salt in a small bowl until dissolved. Fold into the rested rice gently using a wooden spatula.

Dice fresh salmon fillet into small cubes and mix in a bowl with mayonnaise, sriracha sauce, sesame oil, and chopped green onions, stirring gently to combine.

Preheat the oven to 375°F (190°C). Spread the seasoned sushi rice in a baking dish, pressing down to create a firm base. Layer the salmon mixture on top.

Bake for 25-30 minutes until the top is golden brown and slightly bubbly. Monitor closely to avoid burning.

Let it cool for a few minutes before garnishing with additional green onions and nori strips. Serve warm with pickled ginger and soy sauce.