Make the sweet potato frosting: Preheat the oven to 425°F. Use a fork to poke a few holes into the sweet potato. Place on a baking sheet or on a piece of foil and roast until very tender, about 60 minutes. Let the potatoes cool slightly, then measure 3/4 cups of the soft flesh. In a (small) food processor, puree the sweet potato, chocolate chips, cocoa powder, coconut oil, and salt. The heat of the sweet potato will melt the chocolate.
Make the cake. Reduce the oven heat to 350°F and grease an 8x8 baking pan.
In a large bowl, stir together the flours, cocoa powder, baking soda, salt, and cinnamon. To the same bowl, add the almond milk, maple syrup, olive oil, apple cider vinegar, and vanilla. Stir until combined.
Pour the batter into the prepared cake pan and bake for 25 to 30 minutes, or until the top of the cake springs back when pressed or a toothpick inserted in the center comes out clean. Place the pan on cooling racks and cool for 10 minutes.
Gently loosen the sides of each cake with a knife. Remove the cakes from the pan and place back on the racks to cool completely. Frost the cake and serve!