Homemade sushi, made in minutes. If you're looking for ponzu sauce, it can be found in the Asian aisle of most grocery stores. Enjoy!
With a vegetable peeler, peel the cucumber into long strips. (Once you hit the seeded center, flip the cucumber over and peel again. Discard the seeded center, or enjoy for another use.) With a clean paper towel, gently dry cucumber so the pieces are not slippery. Place cream cheese in a large pastry bag. Snip a 1/2" piece from the tip of the bag. Pipe a 1" line of cream cheese just to the left of center on one cucumber slice. Place a slice of krab, jalapeno and 2-3 scallion pieces on top of the cream cheese. Tightly roll cucumber slice around the cream cheese. Secure with a skewer. Repeat until all cucumber slices are rolled. Arrange on a serving platter. Drizzle with ponzu. Place a dot of Sriracha on top of each piece of sushi. Garnish with sesame seeds and extra chopped scallions, if desired.