Vanilla is the pod of a climbing vine and a member of the orchid family. Vanilla extract is made from whole vanilla beans that have been soaked in alcohol. Vanillin is an artificial vanilla flavoring chemically made from wood waste. By United States law, pure vanilla extract must be made from vanilla. Imitations must be labeled. When using imitation instead of pure vanilla extract, double the amount called for in the recipe.
The very best vanilla flavor comes from steeping the vanilla bean in the liquid you are using for cooking. Place a whole vanilla bean in a jar of sugar and it will give the sugar the flavor of vanilla. Long, dark brown vanilla beans can be used a number of times. Just rinse them, dry them off, and keep them in an airtight container.
Burt suggests the following:
Madagascar Vanilla Beans
Madagascar Vanilla Extract