Preheat the oven to 350°F. Line a large baking sheet.
In a bowl, mix together the flour, salt and cinnamon plus any other Add Ins.
In a separate bowl, mash together the cooked sweet potato with egg and water.
Add the dry ingredients to the wet ingredients. Using your hands or with a handheld of stand mixer with paddle attachment, mix until you have a dough that is not sticky and you can roll out. You can always add more flour or water if needed.
Rollout the dough onto floured surface until ¼-inch thick. Use floured cookie cutter or a knife to cut into small shapes. Re-roll all scraps.
Bake 20 to 25 minutes until completely cooked though. These are hard treats, not soft. Cool and store in an airtight container.