Rinse the rice under cool water for 30-45 seconds, or until the water runs clear. 

Add the rice and water to a rice cooker and cook according to the bag instructions. If you don’t have a rice cooker, add the rice and water to a small saucepan set over medium-high heat. Bring the water to a boil and then reduce the heat to low. Cover with a lid and simmer for 18-20 minutes, or until the water is absorbed and the rice is tender. 

Add the cooked rice to a large bowl and drizzle over the rice vinegar. Stir to combine. Set the rice aside and cool completely before assembling the sushi bowls. 

To assemble the sushi bowls, divide the rice between four bowls. Top with avocado, imitation crab, and cucumber. 

Whisk together the mayonnaise and sriracha in a small bowl. If you prefer a thinner sauce (one that you can drizzle), whisk in 2 tablespoons of water. 

Serve the sushi bowls with spicy mayo on the side or drizzled on top. Garnish with sesame seeds, green onion, or nori furikake. 

Enjoy immediately. I do not recommend storing these bowls overnight as the rice will dry out and the avocado will brown. These bowls are best enjoyed immediately after assembly.