Rinse sushi rice in a fine-mesh strainer until the water runs clear. Transfer to a medium pot with water and bring to a boil over medium-high heat.

Cover and reduce heat to low. Simmer for about 18 minutes until water is absorbed and rice is tender. Let sit covered for 10 minutes.

Mix rice vinegar, sugar, and salt in a small bowl until dissolved. Gently fold into warm rice with a wooden spatula.

Slice half a cucumber into thin matchsticks and dice the ripe avocado into cubes.

Layer seasoned sushi rice in medium-sized bowls and top with chopped cucumber, diced avocado, and crab meat.

Drizzle soy sauce over the bowls, adding sriracha if desired. Serve immediately for the best experience.