Easy Overnight Bacon and Egg Breakfast Casserole Recipe. Grease a 9" x 13" baking dish. Mix together the eggs, milk, salt and dry mustard. Spread the bread cubes in the bottom of the dish, sprinkle over the bacon and cheddar cheese. Pour the egg mixture over the top. Cover with plastic wrap and refrigerate overnight, then bake at 350 F for 45 - 60 mins.