Place bacon in a large skillet and cook over medium-high heat, turning occasionally, until evenly browned, about 10 minutes. Drain bacon slices on paper towels and crumble.
Beat eggs in a bowl and stir in milk. Season with salt and pepper. Add bacon, hash browns, and 1/2 of the Cheddar cheese. Butter a casserole dish and press mixture into the dish. Top with the remaining cheese.
Cover casserole and refrigerate to let flavors mingle, 8 hours to overnight.
Preheat the oven to 350 degrees F (175 degrees C). Uncover the casserole.
Bake in the preheated oven until eggs are set, 1 1/2 to 2 hours.