Preheat the oven to 375°F (190°C) and lightly spray a baking dish with nonstick cooking spray.

In a saucepan, bring 2 cups of water or vegetable broth to a boil. Add quinoa, reduce heat to low, cover, and simmer for about 15 minutes until fluffy.

In a large bowl, mix cooked quinoa, black beans, corn, diced tomatoes, half the cheese, cumin, chili powder, salt, and pepper.

Cut tops off bell peppers and remove seeds. Place them upright in the baking dish and fill each with the prepared mixture.

Cover with foil and bake for 25 minutes. Remove foil, sprinkle remaining cheese on top, and bake uncovered for another 10 minutes until heated through.

Allow cooling slightly before serving; drizzle with avocado crema or salsa if desired.