In a large bowl, stir the flaxseed meal and water until combined, and set aside until thickened, about 10 minutes. Stir in the 1 1/2 cups of banana puree, flour, cacao, sugar, baking powder, salt and the 2 tablespoons of coconut oil until combined. Transfer the batter to the baking pan and use a small offset spatula to smooth the top of the batter. Sprinkle with the shredded coconut. Bake for about 40 minutes, or until the brownies are firm at the edges and have begun to set in the center.