Set the chicken breasts on a cutting board and lightly coat them with the oil.
In a small bowl, mix the paprika, ½ teaspoon of the salt, garlic powder, and onion powder. Season both sides of the chicken with this blend.
With a sharp knife, create a pocket in the side of each chicken breast. Set aside.
In another bowl, combine the cream cheese, Parmesan, mayonnaise, spinach, garlic, red pepper flakes, and the remaining ½ teaspoon salt until the mixture is smooth and evenly blended.
Fill each chicken pocket with the spinach mixture.
Arrange the stuffed chicken breasts in a 9×13-inch baking dish. Bake uncovered for 25–30 minutes, or until the chicken reaches a safe internal temperature and is fully cooked.