Pre-heat oven to 350 degrees. Spray a large baking sheet with cooking spray and scatter the apples, onions and sweet potatoes in a single layer. Drizzle with 2 tablespoons of the olive oil, 1 teaspoon of the salt, 1 teaspoon of the cinnamon and 1/2 teaspoon of the pepper. Mix well with hands.
Place chicken breasts on top of the veggies/apple mixture and drizzle with remaining olive oil and sprinkle with remaining spices. Rub evenly to coat chicken on both sides.
Bake until chicken is golden and cooked through, about 45-60 minutes depending on thickness of chicken.
Serving size is one chicken breast and 1 cup cooked veggies.