Preheat the oven to 375°F (190°C).
Place the chicken breasts on a cutting board and drizzle with oil.
In a small bowl, mix paprika, 1/2 teaspoon salt, garlic powder, and onion powder. Sprinkle evenly over both sides of the chicken.
Using a sharp knife, carefully cut a pocket into the side of each chicken breast.
In a mixing bowl, combine cream cheese, Parmesan, mayonnaise, spinach, minced garlic, red pepper flakes, and the remaining 1/2 teaspoon salt.
Spoon the spinach mixture evenly into each chicken breast.
Arrange the stuffed chicken breasts in a 9×13 baking dish.
Bake uncovered for 25–30 minutes, or until the chicken is fully cooked and the filling is hot.