Rinse 2 cups of short-grain white rice under cold water until the water runs clear. Cook the rice in a rice cooker with 2 cups of water for 20 minutes. In a saucepan, heat 1/4 cup rice vinegar, 2 tablespoons sugar, and 1 teaspoon salt until dissolved, then fold this mixture into warm rice and cool.

Wrap a bamboo sushi mat in plastic wrap. Fill a small bowl with water mixed with a splash of vinegar. Gather fillings like imitation crab, avocado, and cucumber for assembly.

Place a sheet of roasted nori, shiny side down, on the sushi mat. Spread a thin, even layer of cooled sushi rice over the nori, leaving about 1 inch at the top edge bare. Flip the nori over so the rice is facing down, and line fillings across the center.

Lift the edge of the bamboo mat with your thumbs while holding the fillings in place with your fingers. Roll tightly away from you, applying pressure. Moisten the bare edge of the nori to seal the roll.

Brush the top of the roll with spicy mayo or eel sauce. Sprinkle toasted panko breadcrumbs or French fried onions on top and press down gently with the mat.

Using a sharp knife dampened with water, slice the roll into 8 equal pieces. Wipe the knife with a damp cloth between cuts for clean edges. Serve with soy sauce, pickled ginger, and wasabi.