Make the Rice: Rinse the rice until the water runs clear. Cook in a rice cooker or according to package directions with the strip of kombu. Combine the rice vinegar, sugar, and salt in a small bowl, then fold it into the cooked rice with the sesame seeds. Discard the kombu. Cover and refrigerate for at least 3 hours, overnight is preferred.

Crab Tampico: Combine the crab, Japanese mayo, sesame oil, chopped serranos, scallions, cilantro, rice vinegar, and tamari in a medium bowl. Mix well.

Spicy Salmon: Combine the chopped salmon, Japanese mayo, sriracha, tamari, and sugar in a medium bowl. Mix gently.

Assemble the Bundt: Coat the bundt pan thoroughly with cooking oil spray. Press half of the seasoned rice into the bottom of the pan. Layer in the toasted nori, the crab tampico, the cucumber slices, and the avocado. With wet hands, press the remaining rice on top so it sits flush with the rim. Place your serving plate upside down over the pan and carefully flip everything over, then tap lightly until the cake releases.

Top and Serve: Sprinkle shichimi togarashi over the top. Pipe the spicy salmon onto each raised section and garnish with sliced serranos.