Combine the oat flour and cinnamon powder. Add in the peanut butter and water. Stir to combine and knead the ingredients into a dough with your hands until it sticks together. If it's too crumbly, add more water. If it's too sticky, add more flour.
On a lightly floured parchment paper, roll out the dough. Cut out the individual cookies with a cookie cutter (or use a pizza wheel to make them cracker-sized if you don't have any cookie cutters).
Bake them in the oven for 10-12 minutes. They should be baked all the way through and crispy. Let them cool off before feeding them to your dog!
* You can easily make your own oat flour! Add rolled oats in a blender and pulse until fine!
Storage: You can store these in an air-tight container at room temperature for up to a week or even longer! But let them cool off completely before packing them away.