Vanilla is a ubiquitous ingredient found in almost every recipe for every baked good ever created but, unless you're making a vanilla-focused treat with a large amount of the extract, you can sub in a little bourbon or dark rum.
As Emma Laperruque explains over at Food52, the pod-infused serum's main job is to provide a little bit of complexity and depth. If your recipe only calls for a tiny amount -- a teaspoon or less -- a bit of dark booze can do the same job. Lapperuque recommends using a dark alcohol with a "distinct personality," such as bourbon or rum, but I can't wait to play around with some bitter-sweet amari like Cynar or Nonino. Just be sure to double the dosage; if your recipe calls for a teaspoon, use two.