Set your oven to preheat at 375℉ (190℃). While it heats up, line a large baking sheet with parchment paper to prevent the cookies from sticking.

Peel the large sweet potato and cut it into cubes (about 2 1/2 cups cubed for 1 1/4 cups mashed). Place the cubes in a pan or pot, cover them with water, and bring to a boil. Let them cook until they're soft, about 8-10 minutes. Drain the cubes and return them to the pan, then mash thoroughly using a potato masher.

Add the mashed bananas, oat flour, brown rice flour (or additional oat flour if substituting), old-fashioned oats, maple syrup (if using), and ground cinnamon (if using) into the pan with the mashed sweet potato from Step 2. Stir everything together well. The resulting batter will be quite thick and sticky. I like to add a little extra cinnamon for a more aromatic flavor boost.

Using a cookie scoop or spoon, portion out the dough and form it into balls. Place each ball onto the prepared baking sheet. Gently press each ball down with a fork to flatten and shape the cookies. Bake in the preheated oven for 15-18 minutes, or until the cookies are golden.

Remove the baked cookies from the oven and allow them to cool on the baking sheet for about 5 minutes before enjoying. For extra deliciousness, I sometimes drizzle a little extra maple syrup on top when serving.