Set aside 1 cup of this mixture for making a glaze later. To the rest of the mixture, add the baking powder, vanilla and flour and beat well again.
Pour the prepared cake mixture in an oiled and floured 8″ (20 cm) in diameter oven dish or form with removable sides of the same size. After you pour it in, spread it out well with a spoon, so the cake doesn't bloat in the middle only.
Bake in a preheated 356°F (180 °C) oven (only on the bottom element), with the form right in the middle of the oven. Bake until a toothpick comes out dry when you poke the cake (about 40 min.)
While the cake is baking, pour the mixture you set aside earlier in a pan or pot and put it on a medium hot stove. Crumble the chocolate into the mixture as well (set aside a little of it to grate on top of the cake once ready). Once the mixture starts to boil, while stirring constantly, wait for it to thicken a little and remove from the stove. Leave the cream/glaze to cool completely.
Once the cake is baked, take it out of the oven and leave to cool completely. Once both the cake and glaze are cooled, invert the cake into a suitable plate, cut it into pieces and pour the cream/glaze over it. Decorate with grated chocolate, blackcurrants and the chocolate coconut bar.
Note: My oven isn't that strong and doesn't have a fan, so decide how long to bake based on your own oven.
Before you pour the glaze over the cake, stir it well before that, so it's smooth.
There's no chocolate and decoration in the original recipe. If you like you can leave them out but everything else stays the same.