Line 8×8 glass baking dish with a thin layer of coconut oil to keep from sticking.
In large bowl, mix coconut flower and cacao. Set aside.
In a small pan on stove, melt nut butter with maple syrup. Stir continuously. Add wet ingredients to dry mixture and mix. Stir in mashed sweet potato (or pumpkin) until batter is even. If batter looks too thick, add a tablespoon or more of milk of choice. If batter looks too thin, add a dash more of coconut flour.
Pour batter into baking dish and refrigerate for at least 30 min to set.
While brownies set, make combine ingredients to make frosting.
Store any unused portion in the refrigerator.