There are things they can make that are not on the menu but never heard of a secret menu
Your question is provocative. Starbucks has no menu. It is not a restaurant.
Yes they do have a secret menu you just have to ask them once you get there what's on the secret menu
As long as you can Google the drink you want, and it's ingrediance. then they should be able to make anything you ask for, as long as it's a Starbucks drink.
Thanks! Your answer is awaiting moderation.