Cut the tops off the bell peppers and remove the seeds and membranes. Set aside.
In a large skillet over medium heat, add the ground chicken. Cook until browned, breaking it apart with a spatula, about 5-7 minutes.
Add the cumin, smoked paprika, garlic powder, onion powder, salt, and pepper to the chicken and stir well to combine.
Stir in the cooked quinoa, black beans, corn, diced tomatoes, and half of the cheese. Mix everything together until well incorporated and heated through, about 2-3 minutes.
Spoon the chicken mixture evenly into each of the prepared bell peppers. Place the stuffed peppers upright in a baking dish.
Sprinkle the remaining cheese on top of each stuffed pepper.
Cover the baking dish with foil and bake in the preheated oven for 25 minutes.
Remove the foil and bake for an additional 10 minutes, or until the cheese is bubbly and lightly golden.
Remove from the oven and let cool for a few minutes before serving. Garnish with fresh cilantro if desired.