Season the Chicken: Place the chicken breasts on a cutting board and drizzle with olive oil.
Prepare Seasoning: In a small bowl, mix paprika, ½ teaspoon salt, garlic powder, and onion powder. Sprinkle evenly over both sides of the chicken.
Create a Pocket: Using a sharp knife, carefully slice a pocket into the side of each chicken breast without cutting all the way through. Set aside.
Make the Filling: In a small mixing bowl, combine the cream cheese, Parmesan, mayonnaise, spinach, garlic, red pepper flakes, and the remaining ½ teaspoon of salt. Mix well.
Stuff the Chicken: Evenly divide the spinach mixture and spoon it into each chicken pocket.
Bake: Arrange the stuffed chicken breasts in a 9×13-inch baking dish. Bake uncovered for 25-30 minutes, or until the chicken is cooked through (internal temperature of 165°F).
Serve & Enjoy: Let the chicken rest for a few minutes before serving.