Preheat oven to 350 degrees F.
Melt chocolate and butter on low heat over the stove until just melted and smooth.
Remove from heat and whisk in sugar, for a minute. Test with your finger to make sure it's not too hot, then whisk in eggs, one at a time, whisking as you work. Stir in cocoa powder, teff flour, baking powder and salt. Whisk until no flour streaks remain.
Pour into a parchment lined 8 x 8 baking pan, and bake at 350 degrees for 20 minutes, until toothpick comes outs just clean. Let cool for five minutes in pan on a wire rack, then remove from pan and let finish cooling on the rack.
While brownies are baking, Pour coconut milk and salt into a pa. Over medium hit bring coconut milk to just under a boil, steaming heavily, with little simmer bubbles around the edges.
Place chocolate in a bowl. Pour the coconut milk on top and let sit for about 5 minutes until the chocolate is soft. Gently start to stir in a figure eight motion. (This is important, and prevents air bubbles, which are hard to get rid of and will disrupt the smooth, silky texture. Do this until chocolate is fully incorporated and the ganache is smooth and silky. That's it!