Preheat the oven to 350 degrees and spray a 9x9 baking dish with coconut oil spray. Set aside.
In a bowl, whisk together the sprinkle ingredients and set aside.
In another bowl, whisk together the oat flour 1/2 cup sugar, 1/4 cup cocoa powder, baking powder, baking soda, and salt. Add in the mashed sweet potato, almond milk, and vanilla and stir to combine. Spread this mixture out in your prepared baking dish.
Sprinkle on the sugar and cacao mixture in an even layer. Pour the coffee over the whole cake. Place in the oven and bake for 35 minutes and then let cool for 10 minutes out of the oven. Serve.