Chocolate Orange Muffins

225g / 8 oz plain flour
55g / 2 oz cocoa powder
3 tsp baking powder
115g / 4 oz sugar
1 egg
6 tbsp sunflower oil
7 fl oz milk
Zest and juice of 1 orange
100 - 115g / 4 oz chocolate drops

Preheat oven to Gas Mark 6 / 200 degrees C / 400 degrees F. Sift the flour, cocoa and baking powder into a large bowl. Add the remaining ingredients and mix to a batter. (Do not over-mix the batter. Too much mixing will create tougher muffins.) Divide the mixture evenly between 12 muffin cases in muffin trays. Bake for 15-18 minutes.