Roast the sweet potato: Peel and cut the sweet potato into evenly sized sticks. Toss with oil, soy sauce, maple syrup, garlic powder, smoked paprika, and salt. Roast at 425°F (220°C) for 20–25 minutes, turning once, until tender with lightly browned edges.
Season the sushi rice: While the rice is warm, gently fold in rice vinegar, sugar, and salt. Let it cool until it is comfortable to handle while keeping it slightly warm and sticky.
Toast the panko: Add panko to a dry skillet over medium-low heat. Stir frequently until golden and crisp. Remove from the heat, mix in sesame seeds, and let the crumbs cool.
Make the sauce: Stir mayonnaise and sriracha together in a small bowl. Keep the sauce relatively thick so it does not make the sushi soggy.
Prepare the nori: Place a nori sheet on a bamboo sushi mat with the rough side facing upward. Wet your fingers and spread a thin, even layer of sushi rice over the nori.
Add the filling: Place roasted sweet potato sticks across the lower third of the rice. Add a thin line of spicy mayo and a small amount of toasted panko.
Roll the sushi: Lift the edge of the mat and fold the nori over the filling. Roll firmly but gently, keeping the filling in place. Give the completed roll a light squeeze to help it hold its shape.
Add the crunchy topping: Coat the outside with a light layer of toasted panko. Drizzle with spicy mayo and finish with sesame seeds or sliced green onion if desired.
Slice and serve: Use a sharp, lightly moistened knife to cut the roll into six pieces. Wipe the blade between cuts for cleaner slices. Serve with soy sauce, pickled ginger, and wasabi.
