Combine diced raw salmon, sliced scallions, Kewpie mayo, soy sauce, Sriracha, sesame oil, ginger paste, garlic clove, and cornstarch in a medium bowl, then stir to thoroughly mix. Taste and adjust seasoning as needed.
Dip one rice paper roll at a time into a shallow bowl filled with warm water. Transfer to a cutting board. The rice paper should become easily pliable. Use a sharp knife to cut the rice paper in half.
Place filling on half of the rice paper roll, then, if wanted, add a place of jalapeño right on top. Roll the rice paper over and around the filling to create a little rectangular parcel, rolling it tightly to seal in the filling.
Preheat an air fryer or conventional oven. If using the air fryer, be sure to spray the basket with cooking spray or place a piece of parchment down. Cook, flipping once half-way through, then immediately sprinkle with sesame seeds.
While they’re cooking, combine the sauce ingredients in a small bowl. Enjoy immediately with the crispy rice paper rolls!