In a large mixing bowl, mash the black beans using a fork or potato masher until mostly smooth with some chunks remaining.
Add breadcrumbs, nutritional yeast, finely chopped onion, bell pepper, minced garlic, ground cumin, chili powder, smoked paprika, salt, and pepper to the mashed black beans.
In a glass or cup, stir 1 teaspoon of arrowroot into 2 tablespoons of water until blended.
Mix in arrowroot water, soy sauce or tamari, tomato paste or ketchup, and olive oil. If you like some heat, add hot sauce or cayenne pepper to taste.
Divide the mixture into 4 equal portions and shape each portion into a patty. If the mixture feels too wet to handle, you can add a bit more breadcrumbs.
Place the patties on a plate and refrigerate them for about 30 minutes. Chilling helps the patties hold their shape during cooking.
Heat a bit of olive oil in a skillet over medium heat. Once hot, add the patties and cook for about 4-5 minutes on each side, or until they're nicely browned and heated through.
Toast the burger buns if desired. Place a black bean patty on the bottom half of each bun.Add your favorite toppings such as lettuce, tomato, onion, avocado, vegan cheese, and condiments.