Preheat the oven to 350 degrees. Place the baked sweet potatoes in a bowl and mash with a fork.
Add the cocoa powder, coconut sugar, maple syrup, vegan buttery spread, vanilla extract, baking powder, and salt. Mix until smooth. If the batter seems too thick, add a little water. It should seem like normal brownie batter.
Stir in the dairy free chocolate chips. Spoon the batter into an 8 inch cast iron skillet. Bake at 350 degrees for 27-30 minutes.
Serve the brownie while warm, topped with dairy free ice cream or whipped coconut cream if desired.
Notes
Store leftover brownie in the refrigerator. It should stay fresh for 3 days.If you can't do sweet potatoes, you could try mashed black beans instead.If you can't do coconut sugar, substitute an equal amount of a sugar that fits your dietary needs.