Step 1: Prepare the Oven and Chicken - Preheat your oven to 375°F and lightly grease a 9x13 inch baking dish. Take a quick look at your chicken breasts before putting them into the dish. If some are especially thick, slice them in half lengthwise or gently pound the thickest areas so the pieces are closer to an even thickness. This is worth the extra minute because evenly sized chicken cooks more predictably, and nobody wants one piece dry while another is still trying to reach a safe temperature. Arrange the chicken in a single layer in the prepared dish.
Step 2: Mix the Creamy Seasoned Layer - Add the softened cream cheese and sour cream to a medium bowl. Sprinkle in the garlic powder, onion powder, salt, and black pepper, then stir everything together until the mixture is creamy and fairly smooth. Do not worry if you have a few tiny lumps of cream cheese. They will soften in the oven. Spread this mixture over the tops of the chicken breasts, making sure each piece gets a good coating. This layer helps protect the chicken as it cooks and gives every serving that rich, creamy texture.
Step 3: Stir Together the Cranberry Topping - In a separate small bowl, combine the whole berry cranberry sauce, brown sugar, Dijon mustard, and Worcestershire sauce. Stir until the mustard and Worcestershire sauce are distributed throughout the cranberries. Give it a moment here because this little bowl is where the sweet and savory sides of the dinner come together. Spoon the cranberry mixture over the cream cheese layer, spreading it gently so you get cranberry sauce across as much of the chicken as possible.
Step 4: Add the Cheese and Bake - Sprinkle the mozzarella evenly over the cranberry layer, followed by the shredded cheddar. Try to spread the cheese from edge to edge rather than leaving a big mound in the center. Place the baking dish into the preheated oven and bake uncovered for about 35 to 40 minutes. Cooking time will depend on the thickness of your chicken, so use an instant read thermometer rather than relying only on the clock. The chicken is ready when the thickest portion reaches an internal temperature of 165°F. By then the cheese should be melted and the cranberry mixture should be hot and glossy around the edges.
Step 5: Rest the Chicken and Serve - Take the baking dish out of the oven and let it rest for about 5 minutes before serving. I know that can feel like a long five minutes when everybody is standing nearby asking if dinner is ready, but the short rest gives the juices inside the chicken a chance to settle and lets the creamy topping firm slightly. Sprinkle chopped fresh parsley over the top if you are using it, then spoon each chicken breast onto a plate along with some of that cranberry cream cheese mixture from the baking dish.