[vborovikov]

How about

  [@raw organic cane sugar, @honey]{3%tbsp}

Here square brackets indicate that the ingredient will have variations separated by commas.

[dubadub]

Interesting idea, how about the case when quantity varies for different ingredient? For example 2 tbsp of raw organic cane sugar or 3 honey.

[quisnam]

Good idea. I'd prefer the at sign in front of the brackets, though.

  @[sugar, honey]{3%tbsp}

It should be easier to parse and allows for brackets to be used elsewhere without escapes.