Found this great recipe which results in muffins that are just like the ones you see in the shop. Large, light as air and the perfect dome shape. You need to fill the cases right to the top to get this result and start off with a hot oven to get the initial lift and to prevent them burning, use hot water in some of the tin to produce steam.
I know I’ve mentioned this before but perfect muffins are made in the mixing. Be careful when mixing – less is more in the case of muffins. The more you mix the tougher muffin you will produce.