If you're in a hurry and need some today, here's a simple recipe that will get'er done.
Combine the following in Blender
1/4 cup confectioners' sugar
1 vanilla bean
Seal in a jar, the longer it sets the better the flavor. Most recipes call for only a teaspoon or two of the mix. It can easily be doubled and kept in a spice jar.
However, If you're a baking officiando and you cringe to see vanilla blended with anything else, you can make 100% real vanilla powder as well by simply allowing 3 large whole vanilla beans to dry for 21 days, then grind the whole vanilla beans in a coffee grinder.
This pure vanilla will be extremely strong and you'll need to use far less in your recipe then the quickie blend above. (about 1/2)
Vanilla powder has a very rich, warm, spicy flavor to it. It will be a dark brown, much like ground cinnamon. You'll find it adds marvelous flavor to dishes like macaroons or angel food cake, where adding additional liquids can easily distress the recipe outcome!
Vanilla powder is perfect for homemade dry mixes, particularly if you're giving them as gifts, particularly if the recipient isn't a "baker" and is also perfect for those who prefer not to consume alcohol.