Preheat oven to 375 degrees.
Mash bananas well in a medium size mixing bowl. I use a bean masher.
Mix in applesauce (and opyional vanilla extract).
Stir in oats and cinnamon (and optional flax seed). Add more oats if it appears too wet. This photo shows the consistency I like. Be careful not to overmix as it will make the texture of the cookies rubbery. You want the dough to be well incoporated but stop stirring when you no longer see dry parts. If you're doubling, tripling + the recipe, I suggest using multiple mixing bowls to get the perfect texture. Don't overmix!
Add in your mix-ins of choice if desired, and optional sweetener.
Use a medium sized cookie scoop to form rounds onto a baking sheet fitted with a non stick liner. Flatten rounds slightly with water dampened hand, to the thickness you like. (Getting your hand wet prevents the dough from sticking to your hand). These will not spread, so they will remain the same size.
Bake in your preheated oven for about 13-17 minutes. If I'm doing two trays, I switch their positon after 10 minutes. They should be lightly brown. Cool on tray for a couple of minutes, then transfer to a wire rack to cool completely. They are delicious warm or cold, especially with a tall glass of ice cold almond milk! Enjoy! :)
