1. Prepare the Sushi Rice: Start by thoroughly rinsing the sushi rice in a fine-mesh sieve under cold running water. Swirl the rice with your fingers until the water runs clear. This step is crucial for removing excess starch and ensuring a fluffy, non-sticky texture. Transfer the rinsed rice to your rice cooker or a medium saucepan. Add the 2 ½ cups of cold water. If using a saucepan, bring to a boil, then reduce the heat to the lowest setting, cover tightly, and let it simmer for 15-20 minutes, or until all the water is absorbed. Do not lift the lid during this time. Once cooked, remove from heat and let it stand, covered, for another 10 minutes.

2. Make the Rice Seasoning: While the rice is resting, prepare the seasoning. In a small, non-reactive bowl, combine the rice vinegar, sugar, and salt. Whisk vigorously until the sugar and salt are completely dissolved. You can gently heat the mixture in a microwave for 20-30 seconds to help it dissolve faster, but let it cool slightly before using.

3. Season the Rice: Transfer the hot, cooked rice to a large, non-metallic bowl (a wooden or glass bowl is ideal). Drizzle the vinegar mixture evenly over the rice. Using a rice paddle or a spatula, gently “cut” and fold the seasoning into the rice. Use a fanning motion as you mix; this helps to cool the rice down quickly and gives it a beautiful, glossy sheen. Be careful not to mash or stir the rice, as this will make it gummy. Set the seasoned rice aside to cool to room temperature.

4. Prepare the Spicy Shrimp: Ensure your cooked shrimp are patted dry. If they are large, you can chop them into smaller, bite-sized pieces (about ½-inch chunks). In a medium bowl, combine the Japanese mayonnaise, Sriracha, toasted sesame oil, and soy sauce. Whisk until smooth and creamy. Add the chopped shrimp and the finely chopped green onions to the bowl. Gently fold everything together until the shrimp is evenly coated in the spicy sauce. You can taste and adjust the seasoning now, adding more Sriracha for heat or a touch more mayo for creaminess.

5. Prep the Assembly Ingredients: Halve the avocado, remove the pit, and dice the flesh into small, ¼-inch cubes. To prevent browning, you can toss it with a tiny squeeze of lemon or lime juice. Finely dice the English cucumber into similar-sized cubes. Have your toasted sesame seeds, nori strips, and any other garnishes ready to go.

6. Assemble the Stacks: This is the fun part! You will need a food ring mold (about 3 inches in diameter) or a 1-cup dry measuring cup to build your stacks. Place the mold directly onto your serving plate. Lightly wet your fingers or a spoon with water to prevent the rice from sticking. Press about ½ to ¾ cup of the seasoned sushi rice firmly into the bottom of the mold, creating a compact, even layer.

7. Layer the Ingredients: On top of the rice, add a layer of the diced avocado, gently pressing it down to compact it. Follow with a layer of the diced cucumber, again pressing gently. Finally, spoon a generous amount of the spicy shrimp mixture over the cucumber layer, spreading it to the edges of the mold.

8. Reveal and Garnish: Carefully and slowly lift the food ring mold straight up to reveal your beautiful sushi stack. Garnish the top generously with toasted sesame seeds, crumbled nori, extra chopped green onions, a sprinkle of furikake, and a small dollop of masago or tobiko if using. Repeat the process to create the remaining stacks.

9. Serve Immediately: Serve the Spicy Shrimp Sushi Stacks right away while the components are fresh. Provide small dishes of soy sauce, pickled ginger, and wasabi paste on the side for dipping and cleansing the palate between bites.