Place the uncooked short grain rice in a medium sauce pot. Rinse the rice well and drain off as much water as possible.
Add 2 cups of fresh water, place a lid on the pot, and bring to a boil over high heat. Once boiling, turn the heat down to low and let simmer for 15 minutes. After 15 minutes, turn the heat off and let the rice rest, undisturbed and with the lid in place, for 10 additional minutes.
To prepare the sushi rice dressing, combine the rice vinegar, sugar, and salt in a small bowl. Stir until the sugar is dissolved. If needed, microwave for 15-30 seconds to help the sugar dissolve.
While the rice is cooking, prepare the toppings. Shred or chop the imitation crab, shred or julienne the carrot, slice the avocado, slice the cucumber, and break the nori snacks into smaller pieces. Stir together the mayonnaise and sriracha in a small bowl.
When the rice is finished cooking, sprinkle about 1/4 of the vinegar dressing over the rice, then gently fold or stir the rice to combine. Repeat the process until all of the vinegar dressing has been incorporated into the rice.
To build your sushi bowls, place about 1 cup of the seasoned sushi rice in a bowl, then top with crab stick, carrot, cucumber, avocado, a few pieces of nori, a pinch of sesame seeds, and a drizzle of the sriracha mayo.