2) Spread the coconut on a nongreased baking sheet and put in the oven to toast until lightly brown and fragrant (about 10 minutes). Remove from the oven and reserve.
3) Put 175ml of the chocolate and the butter and 1 tbsp of the coconut extract in a double boiler being careful not to let the bowl that the chocolate mixture is in come in contact with the boiling water. Stir until all the chocolate is melted and the mixture is smooth and glossy. Take off the heat and allow to cool slightly, about 2 to 3 minutes.
4) Use an electric mixer with the whisk attachment to beat the eggs, yolks, sugar, and remaining 2 tbsp of coconut essence at low-medium speed for 2 to 3 minutes. Increase the speed to high and beat until the egg mixture becomes pale and thick, about 5 to 8 additional minutes. Reduce the speed back to the lowest setting (we don't want a cloud of flour in our kitchen!).
5) Gradually sift in the flour while mixing, add the chocolate mixture to the egg mixture and beat again until completely incorporated and the mixture is thick and glossy, being careful not to overmix (about 5 minutes). Carefully fold in the toasted coconut.
6) Fill each prepared custard cup about half way, place a few of the remaining chocolate chips into each custard cup. Top off each with the remaining batter. Place all the custard cups on a baking dish that is at least 1cm deep (in case of any spills). Bake the cakes until the edges are set and the centre is still slightly jiggly (about 12 minutes).
7) Leave to cool slightly making sure you don't cool the cakes too much, they're best served warm. Carefully run a knife around the edges to loosen the cake and invert onto individual plate. Dust with icing sugar and more toasted coconut flakes, if desired.