Some vanilla extract are also not vanilla but made from cloves. Weird but true. Don't know how they do the chemistry. It was put out in the open by a famous chef a few years back.

What I can vouch for, personally, is making your own vanilla extract at home, using alcohol. Don't recommend vodka but I recognize it is a widely available and usually affordable alcohol; tried it and the end result was disappointing.

To tie into your comment, I'd also consider cream crackers. Eat a couple first to establish a base line for your palate, then put a drop of extract on another and chew slowly