(Y)ou can get your McDonald’s biscuit sandwiches (or any breakfast sandwich, for that matter) made with a 100% real egg, cracked and cooked fresh on-premises. All you’ve got to do is tell the cashier that you’d like your sandwich made with a “round egg” and they’ll replace your folded egg patty with a real egg, free of charge.
Comparison image attached. Not sure if it’s always free, so your results may vary.
The yellow patty is made from whole eggs, presumably a long time ago. The round egg is made from an egg, today. For an even fresher egg my typical emergency McDonalds breakfast is a side of scrambled eggs and an order of extra crispy bacon, both of which are made when I ask for them.