who's got a good chocolate muffin recipe?

Next few days planning on making this recipe courtesy of Ms. Nigella Lawson (but with the addition of Nutella inside).

Any thoughts on other recipes (or this one)?

250g (1 3/4 cups) plain flour (I used 1/2 plain flour, 1/2 wholemeal flour)
2 tsp baking powder
1/2 tsp baking soda
2 tbsp cocoa powder
175g (1 3/4 cups) caster sugar
150g chocolate chips
250ml (1 cup) milk
90ml (over a 1/3 of a cup) vegetable oil
1 large egg
1 tsp vanilla extract
Preheat the oven to 200˚C and line a muffin tray with paper cases.
Combine the plain flour, baking powder, baking soda, cocoa powder, caster sugar and chocolate chips in a large bowl. Whisk the milk, vegetable oil, the egg and vanilla extract in another bowl.
Pour the wet ingredients into the dry and mix till the mixture just turns runny. Spoon the mixture into the muffin cases.
Bake for 20 minutes or a toothpick inserted into the centre of the muffin comes out clean.