Suppose I'm giving a recipe (let's say, for a special cake) to a friend. I'd like to make sure he follows the recipe precisely down to the last minute detail.
Is there an idiom that I could use to express this? As in, "But you have to follow the instructions of the recipe ___!"?
To the letter is often used here.
exactly as instructed; exactly as written.
One of the examples on The Free Dictionary is even about a cake recipe:
We didn't prepare the recipe to the letter, but the cake still turned out very well.
"To a 'T' " is another saying, but 'To the letter is the better answer'.
