There are 4 main secrets for making the perfect chocolate muffins. 1- Don't over mix the batter or overbake the muffins: Overmixing the batter cause the muffins to turn out dry and chewy. 2-Use oil in making the muffins or half oil and half butter: Using oil help in keeping the muffin moist for a long time. 3- Use good quality baking powder: It is essential to make the muffins rise and help in giving them a fluffy texture 4- Don't overbake the muffins: As long as a toothpick entered in the centre of the muffin come out clean, it is done.