Mash drained and rinsed black beans with a fork or potato masher.
Stir mashed beans, egg, bread crumbs, dried onion, garlic powder, and oil together until combined.
Shape into 4 equal-sized patties, then wash hands.
Bake patties for 10-15 minutes, flip patties halfway through.
Heat a skillet over medium heat, and spray with nonstick cooking spray.
Place baked patties in the skillet and cover with a lid. Cook patties for 5 minutes on the first side, then flip patties and cook for 5 more minutes on the other side.