01 - Mash black beans in a large bowl using a fork or potato masher until mostly smooth, leaving some chunks for texture.
02 - Add chopped red onion, garlic, breadcrumbs, oats, egg, cumin, smoked paprika, chili powder, salt, pepper, and cilantro. Mix until thoroughly combined.
03 - Divide mixture into 4 equal portions and form into burger patties, pressing firmly to hold shape.
04 - Heat olive oil in a non-stick skillet over medium heat. Cook patties for 4–5 minutes per side until golden brown and heated through. Add cheese slices during the final minute and cover to melt.
05 - Lightly toast burger buns until golden and crispy.
06 - Spread mayonnaise and ketchup on toasted buns. Layer lettuce, black bean patty with melted cheese, tomato, avocado, red onion, and pickles. Top with remaining bun half.
07 - Serve immediately while hot, accompanied by sides of choice.