Preheat the Oven:
Preheat your oven to 375°F (190°C).
Prepare the Sauce:
In a medium saucepan, whisk together the chicken broth, cream of chicken soup, cream of celery soup, and milk.
Season with garlic powder, onion powder, salt, and pepper. Heat over medium heat until warmed through.
Assemble the Chicken Layer:
Spread the shredded chicken evenly in the bottom of a 9x13-inch baking dish.
Pour the prepared sauce over the chicken.
Prepare the Dumplings:
In a large mixing bowl, whisk together the flour, baking powder, and salt.
Cut in the cold butter using a pastry cutter or fork until the mixture resembles coarse crumbs.
Add the milk gradually, stirring until a soft dough forms.
Add Dumplings:
Drop spoonfuls of the dumpling dough over the chicken and sauce layer.
Bake:
Cover the baking dish with aluminum foil and bake for 20 minutes.
Remove the foil and bake for an additional 15–20 minutes, or until the dumplings are golden brown and cooked through.
Serve:
Let the casserole cool for 5 minutes before serving. Enjoy warm!