Preheat the Oven: Preheat your oven to 375°F (190°C) and grease a baking dish with non-stick cooking spray.
Prepare the Chicken: Season the chicken breasts with garlic powder, onion powder, salt, and pepper on both sides.
Make the Filling: In a mixing bowl, combine the softened cream cheese, mayonnaise, shredded cheddar cheese, shredded mozzarella cheese, chopped green onions, and crumbled bacon. Mix until well combined.
Stuff the Chicken: Slice a pocket into each chicken breast, being careful not to cut all the way through. Stuff each pocket with a generous portion of the cheese and bacon mixture, using a spoon to press it down and ensure even distribution.
Secure the Chicken: If needed, you can use toothpicks to secure the openings of the chicken breasts to prevent the filling from oozing out during bakin