<ul data-eligibleForWebStory="false">Former McDonald's corporate chef, Mike Haracz, shared some secrets about the fast-food chain during an interview with Delish.Some McDonald's locations sell chocolate and vanilla birthday cakes, but there's no secret menu despite rumors.Haracz shared ordering hacks like adding Big Mac sauce to the Filet-O-Fish and how to replicate McDonald's burger seasoning at home.A key revelation was that fresh-cracked eggs are used for the Egg McMuffin, highlighted as the best quality option for customers.