In a large mixing bowl, roughly mash the drained black beans using a fork or potato masher. Leave some beans mostly intact for texture.
Add the corn, diced red onion, minced jalapeño, panko breadcrumbs, egg, chili powder, and ground cumin to the mashed beans. Stir well until all ingredients are evenly distributed and the mixture holds together.
Divide the mixture into 4 equal portions. Use your hands to firmly shape them into round burger patties.
Heat a lightly oiled skillet or grill pan over medium heat. Place the patties in the pan and cook for 4 to 5 minutes on each side, until deeply browned and heated through.
Place each cooked patty onto a toasted sesame seed bun.
Top the burgers with lettuce, sliced avocado, diced tomatoes, and a spoonful of salsa before serving.