Preheat oven to 400F, grease a mini muffin pan with oil and set aside. You could also use a regular size muffin tin, the ratio of crispy outside to chewy inside will just be different.
Put all the ingredients in a blender, and pulse until smooth, scraping down sides of blender if necessary. Putting your wet ingredients before the tapioca flour will help the mixing process. Tapioca flour behaves similar to cornstarch when mixed with liquids, so make sure it gets mixed well.
Pour batter into the muffin tin, each between half and ¾ way full. It will still be fine if you fill close to the top, but they will expand and puff up quite a bit either way so it will change the shape of the final product.
Bake for 15 minutes or until lightly browned, if using the mini muffin tin it might cook faster, and the regular size muffin tin might take longer. Once cooked remove from oven and let cool slightly before serving. Save leftovers in airtight container, can reheat them for 5 seconds in microwave.
This recipe will make more than one mini muffin pan, make more batches until you are out of batter, and you can freeze the finished puffs for up to one month.