Start by rinsing sushi rice under cold water until the water runs clear. In a medium saucepan, combine the rinsed rice with water and bring it to a boil. Once boiling, reduce the heat to low, cover, and simmer for 20 minutes until the rice is tender. Afterward, mix in rice vinegar, sugar, and salt until fully dissolved.

While the rice is cooking, prepare the avocado and cucumber layer. In a mixing bowl, mash avocado, then add diced cucumber and lime juice. Season with a pinch of salt, stirring gently to combine.

In a separate bowl, dice cooked shrimp and combine it with mayonnaise and sriracha, stirring until the shrimp is well-coated.

Using a round mold or a clean, empty soup can, start with a layer of sushi rice, pressing it down firmly. Follow with a layer of the avocado and cucumber mix, then add the spicy shrimp mixture on top.

Sprinkle a generous amount of furikake over the shrimp layer. Carefully lift the mold off, allowing your Stacks to stand tall. Serve with soy sauce and pickled ginger on the side.