(Optional) If you don't have oats flour available, then you can make your own by pulsing the the old fashioned Quaker Oats in a food processor. It takes just a few pulses, and you have you own Oatmeal available at home.
Roughly break the bananas into small pieces and add into a blender with eggs and 1/4th cup of milk. Blend the ingredients into a smooth paste.
Transfer blended mixture to a bowl. Add 1/2 cup of milk and vanilla extract to the same bowl, and mix everything.
Then add the dry ingredients (oatmeal, whole wheat flour, baking powder, salt and ground cinnamon) into the wet ingredients mixture.
Whisk everything together till you get a smooth batter.
Heat a waffle iron (I use Dash Mini Waffle Maker which uses around 2 tablespoons of batter for each waffle). Lightly brush oil on both inner sides of the waffle iron, and pour 2 tablespoons of batter on one side of the waffle maker.
Close the lid, and as per the waffle maker instructions, open the waffle iron once the waffle is cooked (Dash iron takes around 3-4 minutes for each waffle, this can vary by the waffle iron model and brand, so remember to check the instructions booklet for the waffle maker you are using).
Repeat the above 2 steps till all the waffles are made. This batter quantity yields around 11 waffles of mini waffle iron size.
Serve hot, with toppings of your choice, or even freeze for later!