Preheat your oven to 175°C (350°F) and lightly grease a 9×13-inch baking dish.
Prep the chicken: Place the boneless, skinless chicken breasts in a single layer in the prepared baking dish.
Make the garlic butter mixture: In a small bowl, whisk together the melted unsalted butter, olive oil, minced garlic, Italian seasoning, garlic powder, salt, and black pepper.
Coat the chicken: Pour or brush the garlic butter mixture evenly over each chicken breast, ensuring they are well coated and some of the garlic sits on top.
Bake: Bake uncovered for 25 to 30 minutes (depending on the thickness of the breasts), or until the chicken is cooked through and reaches an internal temperature of 74°C (165°F).
Serve: Garnish with fresh chopped parsley and spoon the flavorful pan juices over the chicken before serving warm.