Grease a box mould (30 cm long; approx. 2 l capacity) and dust with flour. Preheat the oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Mix 200 g flour, grated coconut and baking powder. Cream 150 g butter and sugar with the whisks of the mixer. Stir in eggs one at a time. Add flour mixture and coconut milk alternately and mix everything to a smooth dough.
Fill the dough into the form, add the jam by the spoonful and loosely fold in with the spoon. Bake in a hot oven for 50-60 minutes (test with chopsticks!).
Remove, leave to rest in the mould for approx. 10 minutes, turn out onto a cake rack and allow to cool. Chop the chocolate and melt in a hot water bath. Pour in strips over the cake and let it cool down.