Preheat oven to 375 degrees. Line a large rimmed cookie sheet with aluminum foil and top with a wire baking rack.
Slice chicken breasts thinly in half to create two thin breasts. You will have 8 total after slicing. Sprinkle each piece of chicken with salt, pepper, and garlic powder.
In a medium sized bowl, mix together the cream cheese, spinach, artichoke hearts, garlic, mozzarella, and parmesan.