01 - Preheat oven to 400°F. Lightly grease a 12-cup muffin tin or insert silicone liners.
02 - Rinse sushi rice under cold water until the water runs clear. Combine rice and water in a saucepan, bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes. Remove from heat and let sit covered for 10 minutes.
03 - Mix rice vinegar, sugar, and salt in a small bowl. Microwave for 30 seconds until dissolved. Drizzle evenly over the warm rice and gently fold to combine. Let the seasoned rice cool to room temperature.
04 - Place salmon fillet on a foil-lined baking sheet. Combine soy sauce, sesame oil, honey, ginger, and garlic. Brush mixture over the salmon. Bake for 12 to 15 minutes or until the salmon is just cooked through. Flake the salmon with a fork and stir in the green onions.
05 - Cut each nori sheet in half to make 12 strips. Gently press a nori strip into each muffin cup so the edges extend above the rim.
06 - Add a generous tablespoon of seasoned rice to each nori-lined cup and press down gently. Top with a spoonful of flaked salmon, then add a slice of avocado and a few cucumber strips.
07 - Sprinkle each cup with toasted sesame seeds. Bake sushi cups for 5 minutes, just until the nori crisps and the filling is warmed through.
08 - Let sushi cups cool for 2 minutes. Carefully remove from muffin tin. Serve with soy sauce, wasabi, and pickled ginger if desired.