Preheat the oven to 200C and fill a 12-bun muffin tray with paper cases.
Weigh out the dry ingredients into a large bowl. Pour all the liquid ingredients into a measuring jug.
Mix both together – it will be a runny batter – then spoon into waiting muffin cases.
Sprinkle more chocolate chips on top then cook for 20 minutes or until the muffins are risen and springy.