In a medium pot, prepare the sushi rice according to package instructions. (It usually requires 2 cups water for every 1 cup rice.) Fluff with a fork and set aside.
To a medium bowl, add the hearts of palm, sriracha, and vegan mayo. Mash with a fork until well combined.
In a small bowl, combine the rice vinegar and sugar. Stir to combine. Add the vinegar mixture to the cooked rice and stir to combine.
Assemble your California roll in a bowl by adding seasoned rice to the bottom of a small serving bowl, followed by the cucumber, mango, carrot ribbons, avocado cubes, edamame, shredded nori, and hearts-of-palm "crab." Drizzle the Carrot Ginger Dressing over the top. Garnish with sesame seeds and cilantro, and enjoy!