Line a mini muffin pan with 24 paper liners. Set aside.
In a microwave safe bowl, melt the Nutella and coconut oil in the microwave in 30 second intervals until smooth.
Divide evenly into the prepared muffin pan and sprinkle around 4-5 mini M&Ms into each cup. Transfer the pan to the freezer to harden. Remove from the freezer and transfer to an airtight container. Store in the freezer or the fridge.