01 -
Combine the sushi rice and water in a saucepan. Bring to a boil, cover, and reduce to a low simmer for 15 minutes. Remove from heat and let stand covered for 10 minutes.
02 -
Heat the rice vinegar, sugar, and salt in a small pan until dissolved. Fold into the warm rice using a slicing motion. Spread on a tray and cool to room temperature.
03 -
Line an 8-inch springform pan with plastic wrap, letting excess hang over the edges. Place a nori sheet on the bottom.
04 -
Press half the rice over the nori in an even layer. Top with half the avocado slices, brushing them with lemon juice, then half the salmon. Repeat with the remaining rice, avocado, and salmon.
05 -
Refrigerate the cake for at least 30 minutes so the layers set and the rice firms up.
06 -
Release the springform pan and lift the cake out with the plastic wrap. Peel away the wrap and transfer to a platter. Sprinkle with sesame seeds and scallions.
07 -
Stir together the soy sauce, grated ginger, and sesame oil. Serve in a small bowl alongside the cake.