Preheat oven to 180 degrees C. Line a baking tray with baking paper.
In a food processor, blend the oats until they become a course powder, about a minute or two.
With a fork, whisk together the peanut butter and warm water until well combined. Stir in the blended porridge until smooth. Stir in the wholemeal flour to make a dough.
Turn dough out onto a dusted surface then roll out to the thickness you desire. Cut into desired shape, place on lined baking tray and bake in preheated oven for 10 minutes. Remove from oven, flip over then bake until golden and crispy, about five minutes more. Allow to cool on a wire rack.
The less, the better
I try to use porridge and peanut butter that does not have to many extra ingredients, as it is much healthier for your pet.
I made these for my very small dog, for larger dogs I recommend doubling the recipe and increasing the baking time.