Cook and season the rice

• Rinse the sushi rice until the water runs clear, then cook it according to the package instructions.
• Warm the rice vinegar with the sugar and salt until dissolved, then fold it into the cooked rice and let it cool to room temperature.

Line the pan

• Line the springform pan with the nori sheets, overlapping them so the base and sides are covered.
• Arrange the smoked salmon slices in a single even layer over the nori.

Build the layers

• Spread half of the seasoned rice over the salmon and press it down firmly.
• Add a layer of cream cheese, then the cucumber and avocado slices.
• Top with the remaining rice and press firmly so the cake holds together.

Chill and flip

• Cover and refrigerate until firm.
• Release the pan and flip the cake onto a plate so the salmon layer is on top.
• Sprinkle with toasted sesame seeds and serve with soy sauce.