Vanilla powder consists of vanilla beans that have been dried and powdered. It is intended for use with dry ingredients. It provides a clean, strong vanilla flavor with no moisture and no aftertaste of alcohol. If you absolutely need vanilla flavor in a dry form, then you should seek out vanilla powder or try making your own. If all you want is the vanilla flavor and you are out of vanilla powder, then you should try one of the vanilla powder substitutes below.
Your best bet: Make your own vanilla powder
You can dry vanilla beans simply by leaving them in a location with moving air for a few weeks. To dry them faster than that, you can place them in an oven set to a low temperature. Vanilla beans can be dried in an hour by heating them in an oven set to 150 degrees. The beans can then be placed in a spice or coffee grinder and ground to powder.
The combination of vanilla extract and corn starch can be used to create a less-potent homemade vanilla powder without going to the trouble and expense of buying vanilla beans and drying them yourself. Use twice as much of this vanilla powder as the amount that your recipe requires for a vanilla powder made from ground vanilla beans.
A decent second choice: Whole vanilla beans
Whole vanilla beans are the source of the true vanilla flavor. They come from a vine-like orchid indigenous to parts of Central America. In order to provide the vanilla flavor, the pods must be harvested before they ripen and then aged. As a result of the time-consuming and labor-intensive process required to get them to market, vanilla beans are expensive. That said, most bakers would agree that the cost is worth it as vanilla beans provide the pure and undiluted flavor of vanilla. They do so as much as or better than vanilla powder. You can use them to make your own extract or simply add the seeds directly to a dessert. Using them requires you to split the beans and then scrape the seeds out with the edge of a knife. There is very little moisture, which is one of the main factors that make it an excellent substitute for vanilla powder.
Use the seeds from one vanilla bean pod in place of each teaspoon of vanilla powder in your recipe.
In a pinch: Vanilla paste
Vanilla paste consists of vanilla flavor from two sources: vanilla beans and vanilla extract. It will also have sugar, water, and a thickener. Like vanilla powder, vanilla paste is alcohol-free and therefore all you will get from it is the taste of vanilla accompanied by a mild sweetness from the sugar. There is no aftertaste of alcohol. Because it has been thickened to a paste consistency, it will not add as much moisture to your recipe unlike some of the other vanilla powder alternatives; however, it is still best to use it in desserts that have a moisture component.
Use vanilla paste as a 1:1 substitute for vanilla powder.
Vanilla extract is a solution made by soaking vanilla beans in alcohol in order to extract natural vanillin from them. In addition to standard vanilla extract, there are also double and triple strength versions.
Outside of the US, imitation vanilla flavor is typically referred to as vanilla essence and is made with vanillin. The vanillin in imitation vanilla flavor is typically made from wood pulp or coal tar and has the benefit of being significantly cheaper than vanilla beans or extract made with vanilla beans.