Salmon Sushi Bake

Name: Salmon Sushi Bake
Ingredients: 1 cup sushi rice; 1 1/2 cups water; 1/4 cup rice vinegar; 1 tablespoon sugar; 1 teaspoon salt; 1 - 1.5 pounds salmon (skin removed); 1 tablespoon soy sauce; 1 teaspoon garlic powder; 2 tablespoons cream cheese (softened); 2 tablespoons Japanese mayonnaise; 2 tablespoons sriracha; 1/4 cup furikake seasoning; 2 green onions (chopped); Nori sheets (for serving); Sesame seeds (for garnish); 1 medium avocado (sliced, optional); 1/2 medium cucumber (diced, optional)