In a medium bowl, whisk together the flour, tapioca flour, baking soda and salt.
In a large bowl, with an electric hand mixer, beat the bananas, oil, sugar and vanilla. Add the dry mixture to the wet and mix until just combined. Fold in the chocolate chips. Cover the bowl tightly and refrigerate for 30 minutes.
Preheat oven to 375°F and line a cookie sheet with parchment paper. Scoop the dough into SMALL balls (about 2 tbs) and flatten slightly. Do NOT make the balls too big. Bake for about 8-10 minutes and golden brown. Allow to cool on sheet for 15 minutes.
Notes
Any neutral oil works here like coconut oil or sunflower oil or butter.*You can substitute in corn starch or arrowroot powder for the tapioca flour.You can sub in regular all purpose flour for the oat flour.