In a large bowl, combine the cooked sushi rice, rice vinegar, sugar, and salt. Mix well and let it cool to room temperature.

While the rice is cooling, preheat your oven to 400°F. Line a baking sheet with parchment paper.

Cut the salmon fillet into small cubes. In a skillet over medium heat, add olive oil and sauté the salmon for about 4-5 minutes until cooked through. Season with garlic powder, onion powder, and black pepper. Remove from heat and let cool slightly.

In a separate bowl, mix together the mayonnaise and sriracha to create a spicy mayo.

Once the rice has cooled, take a small amount (about 2 tablespoons) and flatten it in your palm. Place a small spoonful of the sautéed salmon in the center, then mold the rice around the salmon to form a ball. Repeat until all the rice and salmon are used.

Roll each rice ball in panko breadcrumbs until fully coated.

In a large skillet, heat vegetable oil over medium-high heat. Fry the rice balls in batches for about 3-4 minutes on each side until golden brown. Remove and drain on paper towels.

Serve warm, drizzled with spicy mayo and garnished with chopped green onions.