Preheat your oven to 375°F (190°C).
In a mixing bowl, combine the cooked quinoa, mashed black beans, breadcrumbs, olive oil, garlic powder, onion powder, dried oregano, salt, and black pepper. Mix well.
Form the mixture into 4 patties and place them on a baking sheet.
Bake the patties in the preheated oven for 15 minutes, then flip them and bake for another 5 minutes.
Remove the patties from the oven and top each one with marinara sauce and vegan mozzarella cheese.
Return the patties to the oven and bake for an additional 5 minutes, or until the cheese is melted.
Assemble the burgers by placing each patty on a burger bun. Serve immediately.