Preheat oven to 375º
Cream the cream cheese, parmesan, mayo, and minced garlic together in a medium bowl
Stir in spinach
pat the chicken dry and place it on a cutting board
Using a sharp knife, cut a large slit into the long side of each chicken piece, almost all the way through but not quite
Stuff each chicken breast with one-fourth of the spinach mixture
Arrange in a baking dish, and brush with olive oil
Season the chicken: Mix paprika, salt, garlic powder, onion powder, and black pepper together in a small bowl, and sprinkle on top of chicken, rub it over the top and sides of the chicken
Bake in the preheated oven for about 25 minutes, or until the internal temperature is 165°, make sure you take the temp of the actual meat and not JUST the cheesy filling, once you test in the thickest part of the meat