Grease an 8x8-inch baking dish. Layer half of each of these ingredients in this order: potatoes, chicken, broccoli, bacon, onions, and ½ cup cheese. Season layer generously with salt, pepper, and garlic powder. Repeat layers with remaining ingredients and seasoning (set aside ½ cup cheese for the end).
Pour heavy cream over ingredients and sprinkle butter pieces over the dish. Cover with foil.
To eat immediately:
Bake at 350°F for 1 hour or until chicken is cooked through and potatoes are tender. Sprinkle with remaining ½ cup cheese and bake, uncovered, for 5-10 more minutes, until cheese is bubbly.
To prepare and freeze:
Assemble and cover tightly with foil, as instructed, but reserve the last ½ cup of the shredded cheese and store separately in a plastic freezer bag. (Make sure potatoes are covered by the other ingredients so they do not turn black.) Freeze for up to 3 months.
To cook from frozen:
Thaw. Bake, covered with foil, at 350°F for 1 hour, until chicken is cooked through and potatoes are tender. Remove foil, sprinkle with remaining cheese, and bake, uncovered, for 5-10 minutes longer, until cheese is bubbly.