**Preheat oven** to **375°F (190°C)**. Place the **bell peppers** in a baking dish and set aside.
In a **saucepan**, combine **quinoa** and **vegetable broth**. Bring to a boil, then reduce to a simmer, cover, and cook for about **15 minutes**, or until the quinoa is cooked and the liquid is absorbed.
While the quinoa is cooking, in a large mixing bowl, combine **black beans, corn, cumin, chili powder, garlic powder, onion powder, olive oil, lime juice, salt**, and **black pepper**.
Fluff the cooked quinoa with a fork and add it to the bowl with the vegetable mixture. Stir to combine.
Stuff each bell pepper with the quinoa mixture, pressing gently to pack it in.
Cover the baking dish with **foil** and bake for **25 minutes**.
If using cheese, remove the foil after 25 minutes, sprinkle the **shredded cheese** on top of each stuffed pepper, and bake for an additional **5-10 minutes**, or until the cheese is melted and bubbly.
Serve warm, topped with extra **lime wedges** or **fresh cilantro** if desired.