Orange Muffins with Chocolate Chips

1. Preheat the oven to 180 degrees Centigrade (about 355ºF).
2. Butter and flour a muffin pan or line it with muffin cups.
3. Sieve together flour, baking powder, baking soda and salt.
4. Add in orange peel and mix well.
5. In a separate bowl, beat egg till light and fluffy.
6. Whisk in sugar, oil, orange juice and buttermilk .
7. Add the flour mixture to the buttermilk mixture in batches, and fold gently with a rubber spatula till everything is mixed well. Do not over mix the batter.
8. Fold in chocolate chips .
9. Fill each muffin cup till 3/4 full with batter, using a spoon.
10. Place in the oven and bake until a toothpick inserted in the center of a muffin comes out clean, about 20-25 minutes.
11. Transfer to a wire rack and let cool for about 5-10 minutes before removing from the pan.