Place some plastic wrap on a flat surface (using a cutting board works well) and place a sheet of nori on top (shiny side facing down), with a corner pointing up. Sprinkle some kosher salt in the center of your nori. This is optional but gives the Onigirazu more flavor and helps to keep the rice fresher for longer.
Evenly spread the cooked, cooled rice in a thin layer on top of the salt and form into a square shape in the center of nori sheet. In a small bowl, mix together the kewpie mayo and the sriracha. This will create the spicy mayo. Place some on top of the rice and top with some furikake.
Layer two pieces of pan fried tofu (next to each other) on top of the rice and top with some thinly sliced cucumber and some carrots. Top with more rice and repeat the spicy mayo and furikake.
To fold and close: Bring the left and right corners of the nori sheet towards the center. Fold gently but tightly to wrap around the layers at the center. Then bring bottom and top corners towards the center, tucking in the sides like you are wrapping a present. Once you have it wrapped, flip the onigirazu over (loose ends down) and wrap tightly with the plastic wrap.
Let sit for 5 minutes. Using a sharp knife, slice the onigirazu in half. If packing these for a lunch, I slice them in half and then wrap the onigirazu again in plastic wrap to keep them fresh. Enjoy!