Preheat oven to 375ºF. Spray a mini muffin tin with cooking spray or fill with muffin liners.
In a large bowl, combine the muffin mix, water, yogurt, egg and 1/2 cup mini chocolate chips.
Fill each muffin 3/4 of the way full and bake for 12-15 minutes, until toothpick inserted comes out clean. Take muffins out of tin and allow to cool.
If you want chocolate topping: In a small bowl, microwave the other 1/2 cup mini chocolate chips and coconut oil until melted and smooth when stirred. Top each muffin with chocolate.