01 - Preheat oven to 400°F. Lightly grease a baking dish with cooking spray or olive oil.
02 - In a medium bowl, combine cream cheese, mozzarella, cheddar, parsley, thyme, garlic powder, onion powder, salt, and pepper. Mix until smooth and well combined.
03 - Place chicken breasts on a cutting board. Using a sharp knife, cut a horizontal pocket into the thickest part of each breast, being careful not to cut all the way through.
04 - Stuff each chicken breast with an equal amount of the cheese mixture, pressing the filling in gently. Secure openings with toothpicks if needed.
05 - Brush outside of chicken breasts with olive oil. Season with salt, black pepper, and paprika.
06 - Arrange stuffed chicken breasts in prepared baking dish, leaving space between each piece.
07 - Bake for 30-35 minutes until chicken is cooked through (internal temperature reaches 165°F) and tops are golden brown.
08 - Remove toothpicks carefully. Garnish with extra parsley if desired and serve hot.