Preheat your oven to 325 degrees.
In a large mixing bowl, add almond and tapioca flours, baking powder, and salt and mix well.
In a separate bowl, add sugar, butter, egg, water, and vanilla extra. Using a hand mixer on low, mix completely.
Now pour the wet ingredients into the dry ingredient and gently mix until mixed completely. Do not over mix.
Line your baking sheet with parchment paper or a silicone baking sheet, use a small spoon and make into 2 inch sized balls. Bake for 12-15 minutes. They will not brown so don't look for that as an indicator.
Once done, remove from the oven, and place cookies on a cooling rack.
For best results, cool completely before frosting.