Preheat oven to 350 and line a small baking dish (8x8) with parchment paper.
Crack the egg into a mixing bowl and beat with a whisk or fork. Pour in the tahini and maple syrup and stir together with the egg.
Add the cacao powder, baking powder and sea salt to the same bowl, giving the mixture a few gentle stirs to fold the dry ingredients into the wet.
Lastly, stir in the chopped dark chocolate.
The batter will be very thick and sticky. Use a spatula to help transfer the batter into the baking dish. Spread out evenly using the spatula.
The last step before baking in the oven is to sprinkle the sea salt flakes over top. Then bake for 23 minutes.
Remove from the oven and let cool for at least 15 minutes before slicing into brownies. Since we absolutely love flaky sea salt paired with dark chocolate, we sprinkled even more sea salt flakes over top after the brownies baked.