1. Preheat oven to 250 degrees F. Line cookie sheet with foil. Leave sweet potatoes full length (I do for my medium-large dogs), or cut them into smaller pieces for little ones.
2. Evenly distribute the slices on prepared cookie sheet. Sprinkle cinnamon over the potatoes.
3. Cook for two hours at 250 degrees, then flip all the slices and cook for two more hours.
4. Allow the slices to cool on top of the oven. They should dry up and get chewy. Refrigerate unchewed slices.
My dogs love these, and wait around the kitchen licking their lips until they are ready to eat!
Source of recipe: This recipe was inspired by one found in The Bark magazine.