Preheat oven to 350℉. Line an 8x4 inch loaf pan with parchment paper.
In a large bowl, whisk together the sweet potato, applesauce, maple syrup, olive oil, egg and vanilla until smooth. Next, whisk in the brown sugar. Then, add in the oat flour, baking powder, baking soda, cinnamon, salt and mix until incorporated. Transfer the batter to the loaf pan and spread out evenly. Bake for 50-55 minutes or until toothpick comes out clean. Allow to set in the pan for 10 minutes and then transfer to a wire rack to allow to cool completely before adding on the optional frosting.
Chocolate Frosting:
In a small bowl, whisk together the melted butter, maple syrup and vanilla until smooth. Next, add in the powdered sugar and cacao powder and whisk until incorporated and smooth. Frosting should have a thick consistency.