1) Preheat the oven on 200 degrees and gather around 12 muffin cups.
2) Sift the flower, cocaopowder, bakingpowder and salt into a large bowl. Add the chocolate chips and sugar and mix it all together.
3) Mix together the orange zest and juice. Full up the juice with milk until you have 250 milliliters.
4) Beat 2 eggs, add 6 tablespoons of oil and stir the juice/milk mixture in.
5) Make a dent/hole in the middle of the dry ingredients and add the wet ingredients in the middle of the dry ingredients bowl. Stir roughly until everything is just mixed.
6) Fill the muffin cups (12) and bake them in the oven for 20 minutes.
7) In the meantime, make the icing. Melt, in au-bain marie style, the chocolate and butter with the water. Stir the whole time until everything is melted.
8) Remove the mixture from the heat and blend with the icing sugar.
9) Remove the muffins from the oven and spread the icing all over, while the muffins are still hot.
10) If preferred, garnish with some orange zest.
11) Serve the muffins either warm or cold. These make a great dessert.