Source: Minimalista.baked goods
For the batter
2 egg yolks
200 grams light brown sugar
300 grams all purpose flour
5 tsp baking powder
1 tsp butter, at room temperature
200 ml. milk
2 egg whites
For the frosting
200 grams confectioners’ sugar
100 grams semi-sweet chocolate, chopped
130 grams butter
200 ml. milk
200 grams coconut flakes
Preheat oven to 355 °F / 180°C. Prepare a 9″ x 9 ” / 22cm x 22cm baking dish (I greased it and lined it with parchment paper, since I had a squared spring form at hand).
Whisk egg yolks with sugar and butter until fluffy. Mix flour with baking powder. Add flour and milk to the eggyolk-butter mixture and mix until you obtain a homogenous batter. Whisk the egg whites until stiff and then fold them carefully into the prepared batter. Fill the batter into the baking dish and bake around 35-40 minutes, or until the surface becomes evenly golden. Remove from oven and cool about 20 minutes or until lukewarm (can you say so to something solid?). Then cut into even squares. If you wish, remove the crisp sides, so you get all soft and fluffy squares.
While the cake is baking:
Heat milk, butter, chopped chocolate and confectioners’ sugar in a thick-bottomed pot and let simmer a bit. Be careful that the milk does not overshoot, though! This mixture will remain very liquid. Let it cool a bit. Fill a little bowl with coconut flakes.
Once the cake has cooled enough and you cut neat squares, take a fork and dip one square at a time into the chocolate-milk sauce and turn until evenly coated. Then turn it around a few times in the coconut flakes until evenly coated there, too. Cool at least 1 hour on a sheet of baking paper.
Source: word of mouth & combination of various online sources