Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish so it is ready for the chicken. Make sure the dish is large enough to hold the chicken breasts in a single layer without overlapping.
If searing the chicken, heat the olive oil in a large skillet over medium-high heat. Season the chicken breasts with garlic powder, onion powder, salt, and pepper. Sear the chicken briefly for extra color before transferring it to the prepared baking dish. This step is optional. If skipping the sear, simply season the raw chicken breasts and place them directly in the baking dish.
Arrange the seasoned chicken breasts in a single layer in the prepared baking dish. Avoid overlapping the pieces to ensure even cooking and allow the creamy sauce to coat each breast properly.
In a medium mixing bowl, combine the softened cream cheese, chicken broth, Parmesan cheese, chopped fresh parsley, minced garlic, and optional red pepper flakes. Mix thoroughly with a spoon or hand mixer until the sauce becomes smooth and creamy. The original recipe does not specify an exact quantity of Parmesan cheese.
Pour the prepared cream cheese sauce evenly over the chicken breasts. Spread the mixture across the tops of the chicken, making sure each piece receives a generous coating. The cream cheese creates a thick, rich sauce, while the chicken broth helps make it easier to distribute.
Bake in the preheated oven for approximately 30 minutes, or until the sauce is hot and bubbling and the chicken reaches an internal temperature of 165°F (74°C). Use a meat thermometer to check the thickest part of each breast. If the sauce begins browning too quickly, loosely tent the baking dish with aluminum foil while the chicken finishes cooking.
Remove the baking dish from the oven and allow the chicken to rest for a few minutes before serving. Keep the chicken in the baking dish with the creamy sauce during this brief resting period.
Serve the baked cream cheese chicken hot with its creamy garlic sauce spooned over each portion. Pair with rice, pasta, mashed potatoes, or roasted vegetables. Garnish with additional fresh parsley or Parmesan cheese if desired.