preheat the oven to 200 c / 400 f / gas mark 6. Break the chocolate into a bowl and heat over a pan of simmering water untill melted.
Sift the flour and baking powder into a bowl. In a separate bowl add the muscado sugar, melted chocolate,butter,milk and eggs and mix well. Crefully fold in the flour, taking care to not over mix. Stir in the chocolate chips.
Spoon the mixture into paper muffin casesand bake for 25 minutes or until muffins have risen and are firm to touch. remove from the oven and cool for 5 minutes.