Preheat your oven to 350F (175C).
In a large bowl, mix together all of the ingredients, including the flour, eggs, mashed sweet potato, peanut butter, and salt. Once the ingredients are mixed together, slowly add cold water. You want the dough to be slightly dry and easy to roll out. Knead the dough together until it's uniform.
Once mixed, roll out the dough to about 1/2 inch thick. From here, you can cut the treats with your favorite cookie cutter. This recipe yields about a dozen treats, but depending on your cookie cutter, you may get a few more or a few less. Sprinkle with cinnamon if desired.
After cutting, transfer your treats to a parchment lined sheet. Bake them for about 35 minutes, or until nice and crunchy. You can also dehydrate them after baking to make sure that they'll store.
Let them cool completely, and then transfer them to an airtight container. If your dog loves them, you can also make this recipe in larger batches and freeze them.