Preheat your oven to 350°F (175°C).
Rinse the sushi rice under cold water until the water runs clear. Combine the rice and water in a rice cooker or pot, and cook according to the rice cooker instructions or bring to a boil, then reduce heat, cover, and simmer for 20 minutes. Remove from heat and let it sit covered for 10 minutes.
In a small bowl, mix the rice vinegar, sugar, and salt until dissolved. Gently fold this mixture into the cooked rice. Spread the rice evenly in a greased 9x13-inch baking dish.
In a separate bowl, combine the chopped crab sticks, flaked salmon, mayonnaise, sriracha, and green onions. Mix well until combined.
Spread the crab and salmon mixture evenly over the sushi rice in the baking dish.
Bake in the preheated oven for 20-25 minutes, or until heated through and slightly golden on top.
Remove from the oven and let it cool for a few minutes before serving. Garnish with nori squares and sesame seeds if desired.