Preheat oven to 350°F. Butter or spray a 9x9pan, or line with parchment paper.
For the coconut layer: Mix together all of the ingredients. Set aside.
For the brownie layer: In a separate bowl, melt the butter and bittersweet chocolate (in the microwave or on the stove). Whisk in the sugar, then the vanilla, and the eggs (one at a time). Sift together the flour, cocoa powder, and baking powder, and mix into the chocolate mixture just until combined.
To assemble: Pour the brownie mixture into the prepared pan. Gently drop spoonfuls of the coconut mixture onto the brownie mixture and smooth out
Bake for about 1 hour, rotating the pan halfway through and covering with foil if the top starts to brown too much.