Last Sunday, I made an unplanned stop at McDonald’s, hoping to get an early taste of the fried apple pie that’s making a brief return to the menu to mark America’s 250th birthday. It’s one of the secrets of Mickey D’s limited time offerings: They’re often available a couple of days before the official launch date. Sure enough, two days before its formal comeback on Tuesday, the retro hand pie was hiding in plain sight under the “Sweets & Treats” tab on the electronic menu.