Cook the sushi rice according the package instructions. 250 g of uncooked rice yields up to about 3 cups of cooked rice. I measured cooked rice using the standard measuring cup which is 1 cup = 250 ml, not the rice cooker cup.
Using another bowl, add imitation crab, some of the chopped cucumber and chopped mango (reserving some for topping), cream cheese and kewpie mayo. Give it a good mix. Add this to the rice topped with furikake, spread evenly. Add the rest of the chopped cucumber and mango. Add more furikake. Drizzle with sriracha and kewpie mayo.
Remove from the oven, drizzle more Sriracha and kewpie, and top with sliced spring onions. Let it cool down a bit.
Take a spoonful of the sushi bake and place on top of a nori sheet. Enjoy!