Start with preparing the sushi rice. First, rinse 3 cups of sushi rice in cold water until the water runs mostly clear. Then, place the rinsed rice in a medium-sized pot with 4 cups of water and bring to a boil over high heat. Once boiling, reduce the heat to low and let simmer for 30 minutes or until all of the water is absorbed.
Once cooked, turn off the heat and let the rice sit for 5 minutes. Then, transfer them into a large bowl. Drizzle 3 tablespoons of sushi vinegar over the top of the rice and use a spoon or spatula to gently fold it in making sure not to break any grains of rice. Set aside to cool.
In a separate bowl, mix together the mayo and imitation crab until fully combined.
Take four sheets of nori and cut them into ¾ size pieces using kitchen scissors.
Place one sheet of nori on a bamboo mat or cutting board, then spread a thin layer of the sushi rice over it. Leave about 1/2 inch of space on each side.
Spread 4 tablespoons of the mayo and imitation crab mixture evenly over the sushi rice layer.
Place slices of avocado, cucumber, salmon, and ikura over the top of the mayo and imitation crab.
Using your bamboo mat or cutting board, roll up the sushi starting from one side to another. When you reach the end, gently press down on the roll to ensure it stays together.
Slice using a sharp knife into 16 equal pieces and enjoy with wasabi, pickled ginger, and soy sauce.