Mash the black beans in a bowl, leaving some texture. Mix in oats, breadcrumbs, onion, carrot, egg, cumin, paprika, salt, and pepper. Shape the mixture into four patties and refrigerate for 15 minutes. Heat oil in a skillet over medium heat and cook the patties for 4 to 5 minutes per side until golden. Mix the dressing ingredients in a small bowl. Toast the buns, then assemble each burger with lettuce, veggie patty, red onion, pickles, tomato, and dressing. Serve with baked fries, coleslaw, or a fresh green salad. Add jalapeños or hot sauce for a spicy version.