In a medium sized bowl, combine the flour, baking powder, salt, sugar, and zest. Set aside. In a large measuring cup, combine the milk, orange juice and egg and whisk to combine. Melt the butter in the microwave and add it to the milk mixture. Stir until combined. Make a well in the flour mixture and add in the milk mixture. Whisk until combined, and allow to rest for at least 10 minutes. Its ok if its a little lumpy. Preheat a griddle or large pan to medium heat and spray with Pam. Scoop ¼ cup of batter for each pancake onto the pan- the easiest way to do this is with an ice cream scooper. Allow to cook for 2-3 minutes, you’ll know the pancake is ready to be flipped when you start to see bubbles bursting through the top. Flip and cook for 1-2 minutes more. If you want you can add chocolate chips to each pancake as soon as you scoop the batter onto the pan.