Wash and pat dry the sweet potato. Poke it several times with a fork, wrap it in foil, and roast at 400 degrees F for 60 to 70 minutes, or until very soft. Allow sweet potato to cool to room temperature (Note: You can roast the sweet potato up to 3 days ahead of time and keep it in the refrigerator until ready to use).
Preheat the oven to 350 degrees F and lightly oil an 8" x 8" baking dish. Line the baking dish with parchment paper.
Add all ingredients for the brownies except for the chocolate chips to a blender or food processor. Blend until completely smooth. Stir in the chocolate
Transfer the brownie batter to the prepared baking dish. Bake on the center rack of the oven 30 to 35 minutes, or until the center is set up (note: the brownies won't test clean when poked with a fork...this is normal). Turn off the oven and allow brownies to sit another 5 minutes in the warm oven.
Remove brownies from the oven and sprinkle with coarse sea salt (if desired...very much recommended). Allow brownies to cool at least 30 minutes. Pull-on the sides of the parchment paper to release the brownies from the baking dish and transfer to a cutting board. Cut brownies to your desired size and enjoy with a mega scoop of ice cream!