Preheat your oven to 350 degrees.
Prepare cookie sheet lined with parchment/baking paper

Mix dry ingredients in a medium bowl. Add egg, oil and water and stir well.

Roll out on a well-floured surface to 1/2 inch thickness. Place on prepared cookie sheet. Bake on center rack, (275 F. or 140 C) for about 2 hours until dry and very hard.

Let stand overnig

Storing Dog Treats
In general you should store dog treats the same way you would homemade people cookies. That being said, there are two main variables that determine storage time - the amount and type of fat in the recipe and your local weather conditions. If your recipe uses fats such as butter, or meat bits or juices then it will be more prone to rancidity than a recipe that uses some vegetable oil or shortening. Your treats may mold or spoil much faster in humid or very hot climates.

Refrigeration and Freezing - Refrigeration will prolong the life of more fragile dog treats. Make sure to store in a tightly sealed container or zip lock bag. You can also freeze most treats in zip lock freezer bags. Allow to thaw completely before use.ht to dry thoroughly. Store in a tight sealed container for about 2 weeks or freeze for longer storage.