Optional: coarse sugar or additional chocolate chips for topping
Pre-heat oven to 350 degrees.
Add all ingredients to a bowl and mix. Do not overmix.
Spray pan with a light coat of cooking spray if not using liners. Or, insert liners.
Fill a 12 tin cupcake/muffin pan to the top with mixture. Mixture will rise very little. You may want to swirl the top a bit before placing in the oven to get a prettier muffin. Or, sprinkle on some coarse sugar or a few extra chocolate chips for a pretty topping.
Bake for 20-25 min or until a toothpick inserted in center comes out almost clean. It's ok if there is a little melty chocolate on it!