Making the Burgers: In a large bowl, mash black beans with a fork or potato masher until mostly smooth. Add cooked quinoa, breadcrumbs, onion, garlic, smoked paprika, cumin, chili powder, salt, pepper, and egg. Mix until well combined. Form mixture into 4–6 equal-sized patties. Heat olive oil in a skillet over medium heat. Cook patties 4–5 minutes per side, until golden brown and heated through. Remove patties from skillet and let rest for 2 minutes.