Add 3 cups of oats to the bowl of a food processor and chop them until they resemble coarse flour or breadcrumbs. Dump this "oat flour" out into a large bowl.
Add cranberries to the bowl of the food processor and chop until the texture of relish. If you are using dried cranberries, add about a teaspoon of water.
Now add mashed sweet potato, eggs, and coconut oil. Mix until well combined using the food processor.
Add the "oat flour" and spices and mix until well combined.
Add the whole oats last and pulse just a few times to incorporate the oats but not chop them up. It should be a thick, sticky dough
Now, transfer the dough to a separate bowl and cover with plastic wrap. Transfer to the refrigerator and refrigerate the dough for a minimum of one hour.
Once the dough is chilled, preheat the oven to 350°F and flour a surface to roll out your dough. If your dog MUST eat gluten-free, you can use a bit of your favorite gluten-free flour - otherwise, you can just use all-purpose flour or whole wheat flour.
Roll your dough out to about ¼ - ½ an inch and cut out your favorite shapes. You may need to roll it out a few times to use all of the dough.
Place the cookies on a cookie sheet lined with parchment paper or a non-stick baking mat. They won't really expand so they don't need to be too far apart, but they will stick together if they are touching. (If you are not picky about shapes, you can also make cookies by just cutting horizontal and vertical lines like a checkerboard. (Like how you would cut dumplings for soup.) For more detailed instructions on rolling out dog treats, there are tips in my Crunchy Blueberry Dog Treat post. )
Bake in the oven at 350°F for 35 - 40 minutes, until the biscuits are hard/crunchy. Keep an eye on them after 35 minutes - on the lower rack of my oven, some of the treats got a little brown on the edges.
Let the treats cool for a few minutes and then share them with your favorite dog or move them to an air-tight container!