Preheat the oven to 350 degrees F. Grease an 8x8 square pan with oil and set it aside.
In a medium bowl, combine cooked sushi rice and rice vinegar. Mix well and set it aside.
In another medium bowl, combine salmon, imitation crab, cream cheese, mayonnaise, sriracha, and soy sauce. Mix well and set it aside.
Transfer the rice mixture to the prepared square pan and press it firmly to form a uniform layer.
Sprinkle the furikake seasonings evenly over the rice layer.
Spread the salmon mixture over the rice, forming a uniform layer. Bake in the oven for 15-20 minutes.
Once done, allow the baked sushi to rest for 10 minutes.
Meanwhile, prepare the spicy mayo by combining mayonnaise, sriracha, and lime juice in a bowl. Mix well until smooth and set it aside.
Arrange the avocado slices on top of the baked sushi and sprinkle with furikake seasonings. Garnish with green onions and drizzle spicy mayo on top.
Slice the baked sushi into equal squares and serve them on a nori sheet to enjoy.