Rinse sushi rice under cold water until the water runs clear. Combine with water in a rice cooker, boil, then reduce heat and cover for 18-20 minutes. Remove from heat and let sit for 10 minutes, fluff with a fork and mix in rice vinegar.

Heat oil in a skillet over medium-high heat. Add deveined shrimp and cook for 2-3 minutes per side until pink and opaque. Toss cooked shrimp with spicy mayo.

Slice cucumber and avocado into thin julienne strips for preparation.

Assemble the sushi stacks by layering sushi rice in a round mold, followed by spicy shrimp, and then topped with cucumber and avocado.

Garnish with sesame seeds and drizzle with additional spicy mayo if desired. Serve with soy sauce.