Hmmm, I think that alcohol does not have any gluten (a protein in wheat flour that contributes structure to cakes and breads). If you are avoiding alcohol for other reasons, you can make vanilla sugar, use the pods steeped in liquid from the recipe, or maybe try vanilla paste (not sure about the alcohol content, if any, of the paste).
Sponge-type cakes like genoise can be made more easily with gluten-free flours (like cornstarch or cassava) as they derive structure from eggs and starch.
I have heard that butter cakes can be made with gluten-free flours if things like xanthan gum are added, but this seems trickier (and maybe not so tasty?).