Combine all dry ingredients in a large bowl. I used homemade banana chips, so I cut them into fourths as they are rather thick and chewy, but you can use your own digression depending on the type of bananas you use. The cinnamon is to taste, so add more or less depending on your preferences. Additionally, another half cup of old fashioned oats could be used if you don't have buckwheat groats.
Combine the peanut butter and honey in a microwave safe bowl or a small saucepan and cook until melted. Watch VERY carefully as to avoid burning the mixture, if you overheat the honey it will crystallize and ruin the batch.
Add the vanilla to the peanut butter mix and stir well. Combine the melted peanut butter with the dry ingredients, add in the water 1 tablespoon at a time, while continuing to stir, until the entire mixture is moistened.
Transfer the mixture onto a parchment-lined cookie sheet. Bake at 325F for 10 minutes, stir well and return to the oven for another 10 minutes.