Set oven to bake at 350 degrees. Line a large baking sheet with silpat or parchment paper.
In a food processor or blender, add the oats and pulse or chop until you have a flour consistency. Set aside in a small bowl.
1½ cups plus 2 tablespoons old fashioned oats
Add peanut butter and banana to processor or blender and pulse until smooth. Add all but 2 tablespoons of the 'oat flour' to the batter and pulse until combined. If the consistency is too dry, add a bit more peanut butter to dough.
1/2 cup smooth unsweetened salted peanut butter
1 medium banana
Sprinkle the 2 tablespoons of oat flour that was set aside on a cutting board or countertop and turn out dough. With a rolling pin also dusted in the flour, roll out to 1/4" thick and cut with a favorite cookie cutter. Dog bone shaped cutters are very popular for this recipe.
Once all dough has been cut, bake approximately 15 minutes but check it after at 12 minutes since oven temperatures can vary. Biscuit sides should be slightly browned.
Allow to cool one minute before moving to a cooling rack. Can store in air tight cookie jar or freezer safe zip lock bag for 4-5 days. If desired, can freeze for several months.