Preheat the oven to 175°C (350°F) and line a muffin tin with liners.
Put all the ingredients, except the chocolate chips, into a bowl and mix with a spoon or a spatula until all the ingredients are well combined. Fold in the chocolate chips and transfer batter evenly into six muffin tin holes.
Bake in the oven for 15 to 20 minutes until the muffins are slightly browned on top but still very soft on the inside.
Let cool for about half an hour, sprinkle with grated orange zest if you like and enjoy!