In a large bowl, mash the bananas until they are smooth. Then put the tablespoon of apple cider vinegar in the cup of coconut milk and let it sit for a minute. This becomes like vegan buttermilk :) Then add that along with the next 6 ingredients into the large bowl and mix with a whisk.
Prepare two skillets: One large one for the pancakes, one small one for the syrup.
In the small skillet, heat the blueberries and one tablespoon of maple syrup over medium heat. Keep a good eye on this skillet-- once the blueberries start to release their liquid, you will reduce the heat to low and add the other 3 tablespoons of maple syrup and the blueberry balsamic vinegar.
While the syrup is reducing, coat the bottom of the large skillet with olive oil on medium heat. If at any point the cast iron gets too hot, reduce heat. Using a tablespoon, spoon in three pancakes at a time. Once the bottoms are golden brown, flip 'em. Set finished pancakes aside on a covered plate so they stay warm and re-coat the bottom of the pan with Olive Oil.
Meanwhile, how's that syrup? When the temperature is reduced to low and the pancakes are almost complete, dissolve the Tapioca starch in a little bit of water and add to the syrup until you reach your desired thickness.
Serve the cakes 'n' syrup hot!