To start, trim the chicken and place it in a single layer in a large baking dish and season it with salt, pepper and garlic powder.
Place the spinach and mushrooms over the top, then pour the alfredo evenly over the top and finish by sprinkling the bacon and cheese over everything.
Bake at 375˚F for 40-50 minutes on the middle rack. Keep an eye on the top, and if the cheese starts to get browned, place foil over the top loosely for the remainder of the bake time.
Remove from oven and let sit 3-5 minutes, then serve hot over pasta, rice, spinach, mashed potatoes, or your favorite side dish!