Preheat the oven to 350°F. Lightly grease a 9 x 13-inch baking dish with the softened butter.
Add the uncooked rice to the baking dish and spread it into an even layer.
In a large bowl, whisk together the cream of chicken soup, cream of mushroom soup, chicken broth, milk, diced onion, garlic, parsley, thyme, garlic powder, onion powder, salt, and black pepper.
Pour the creamy mixture over the rice and gently stir so the rice is evenly distributed.
Arrange the chicken breasts over the rice mixture. If the breasts are especially thick, slice them horizontally into thinner pieces for more even cooking.
Sprinkle the chicken with paprika and a little additional black pepper.
Cover the baking dish tightly with aluminum foil. Bake for 50 minutes without removing the foil.
Carefully uncover the casserole and check the rice. Continue baking uncovered for 10–15 minutes, or until the rice is tender and the chicken reaches 165°F internally.
Remove the casserole from the oven and let it rest for 5–10 minutes. Spoon some of the creamy rice around the chicken and garnish with fresh parsley before serving.