Drain and rinse the black beans thoroughly under cold running water. Spread on a paper towel to absorb moisture.

In a skillet, heat 1 tablespoon of oil over medium heat. Sauté onions for 3 minutes until soft, then add garlic and cook for an additional minute.

In a large bowl, combine the black beans with the sautéed onion and garlic. Mash the beans until mostly smooth.

Add breadcrumbs, beaten egg (or flaxseed meal), cumin, chili powder, salt, and pepper to the mashed mixture. Mix until well incorporated.

Form the mixture into 4 equal patties, about 1 inch thick. Optionally chill in the fridge for 10-15 minutes.

In a skillet, heat 2 tablespoons of oil over medium-high heat. Cook patties for 4-5 minutes on each side until crispy and golden brown.

Toast burger buns for a minute, then assemble with the patties and preferred toppings.