In a large bowl, combine the ground pork, fish sauce, soy sauce, brown sugar, garlic powder, ground ginger, black pepper, and chopped cilantro. Mix until well combined, but do not overwork the meat.
Divide the mixture into four equal portions and shape each portion into a patty about 1 inch thick.
Preheat your grill or stovetop skillet over medium-high heat. Cook the patties for about 5-6 minutes on each side, or until the internal temperature reaches 160°F.
While the patties are cooking, mix the mayonnaise and sriracha in a small bowl to create a spicy mayo.
Toast the hamburger buns on the grill or in a toaster until golden brown.
Assemble the burgers by spreading a layer of spicy mayo on the bottom half of each bun. Place a pork patty on top, followed by pickled carrots and daikon, cucumber slices, and jalapeño slices if using. Top with the other half of the bun.
Serve immediately with lime wedges on the side for squeezing over the burgers.