In a mixing bowl, combine the softened cream cheese, chopped spinach, artichoke hearts, garlic powder, onion powder, Parmesan cheese, and half of the mozzarella cheese. Mix until well combined. Season with salt and pepper to taste.
Heat olive oil in a large oven-safe skillet over medium heat. Season the chicken breasts with salt and pepper. Sear them in the skillet for 3-4 minutes on each side until golden brown.
Once the chicken is seared, remove it from the skillet and set aside on a plate.
Spread the spinach-artichoke mixture evenly over the chicken breasts, ensuring they're well covered.
Sprinkle the remaining mozzarella cheese on top of the mixture.
Place the skillet in the preheated oven and bake for 20-25 minutes, or until the chicken is cooked through (internal temperature of 165°F or 74°C) and the cheese is bubbly and slightly golden.
Remove from the oven and let it cool for a few minutes before serving. Garnish with fresh parsley if desired.