Preheat oven to 450 degrees F. In small bowl, whisk 2 tablespoons mayonnaise with soy sauce; set soy mayonnaise aside for serving.
Pick over crabmeat to remove any pieces of shell or cartilage. In medium bowl, mix half of green onion, egg white, 2 tablespoons panko, and remaining 3 tablespoons mayonnaise until blended. Stir in crabmeat. Shape into four 3-in. patties. Coat patties with remaining panko, pressing to adhere.
Spray 15-1/2" by 10-1/2" jelly-roll pan with nonstick cooking spray. Lightly spray crab cakes with nonstick cooking spray and place in prepared pan. Bake 15 to 20 minutes or until crab cakes are golden and cooked through, turning over once.
Meanwhile, in large bowl, combine cabbage, vinegar, sesame oil, ginger, and remaining green onion. Serve crab cakes with Asian slaw and top with soy mayonnaise. Serve any remaining mayonnaise on the side.