Vanilla seems to be a very polarizing addition to chocolate, and I'm probably increasing that issue by offering vanilla powder. So be it.
This is 4% organic dried vanilla added to cane sugar.
This is a great and simply way to add a very controllable amount of vanilla to your chocolate. One teaspoon per pound of chocolate seems to be a great starting point. You really can add it at any time but I like adding it about 12 hours into refining. And you do need to refine it or the sugar will be add a bit of grit to your chocolate.
Don't get hung up that you are adding a little extra sugar to your chocolate. At about 5 grams per teaspoon, it is usually insignificant to the recipe proportions.