Preheat oven to 400°F (200°C) and grease a 9x13 inch baking dish.
In a small bowl, combine garlic powder, smoked paprika, onion powder, salt, and black pepper.
Rub chicken breasts with 1 tablespoon of olive oil and coat evenly with the spice mixture.
Place chicken breasts in the prepared baking dish.
Toss sliced bell peppers and onions with the remaining 1 tablespoon of olive oil and arrange them over and around the chicken.
Bake for 20 minutes, or until chicken reaches an internal temperature of 160°F (71°C).
Remove from oven and sprinkle mozzarella and cheddar cheese over the chicken and peppers.
Return to oven for 5 minutes or until cheese is melted and bubbly.
Garnish with fresh parsley and rest for 3 minutes before serving.