Adapted from google.com
cup of canned sweet potato (you can sub fresh if you want)
cups whole wheat flour, brown rice flour, or gluten free flour
If using fresh sweet potatoes: Heat oven to 400 degrees F. Pierce the sweet potato several times with the tines of a fork. Place the sweet potatoes on a rimmed baking sheet lined with foil. Bake until tender, about 45 minutes. Transfer to cooling rack. Reduce oven to 350 degrees F and line a baking sheet with parchment paper. When cool enough to handle, cut the potato lengthwise and use a spoon to carefully scoop out the insides; discarding the skin. Puree the sweet potatoes in a food processor until completely smooth. In a large bowl, whisk together the flour and flaxseed meal. Remove about 1 tablespoons of the egg to a separate cup. Add the sweet potato puree and remaining beaten egg to the dry ingredients and mix until a dough forms. Transfer to a work surface and roll the dough into a 1/2-inch-thick rectangle. Cut mixture using a canine-themed cookie cutter and place on a prepared cookie sheet. Brush with the remaining 1 tablespoon beaten egg. Bake for 25-35 minutes, or until golden brown. Remove to cooling racks and allow to cool completely before storing in an airtight container.