Preheat the oven to 180°C.
Put the oat and spelt flour into a mixing bowl. Add the baking powder, cinnamon and coconut sugar. Combine well.
Peel the mandarin, then purée it in a small food processor. Add the honey, coconut oil, egg and whiz again for a few seconds. Add this mixture to the dry ingredients, together with the grated carrot.
Combine well, then add the milk. Combine and rest until the oven heats up.
Add more milk to the mixture if it’s too dense - it should be thick and light at the same time.
Spoon the batter into a muffin tin, lined with paper cases, or into silicon cups.
Bake for 15-20 minutes until golden brown.
Rest them in the tin for 5 minutes, then transfer the muffins to a wire-rack to cool completely.