Using a food processor, process the onion, bell pepper, and garlic into a paste.
In a large bowl, mash the black beans until mostly smooth. Stir in olive oil, the onion-bell-pepper-garlic-mixture, cumin, parsley, onion powder, soy sauce, ketchup, chili powder, salt, and black pepper.
Mix in the eggs and breadcrumbs until the mixture is cohesive. If the mixture is too wet, add more breadcrumbs as needed.
Divide the mixture into 6 equal portions and shape each into a patty approximately 3/4 inch thick.
Heat olive oil in a large skillet over medium heat. Cook the patties for about 5 minutes on each side, or until they are well-browned and heated through.
Serve the black bean burgers on hamburger buns with your choice of toppings and condiments, such as lettuce, tomato, and mayonnaise.