Preheat oven to 190 C (375 F) and line a mini muffin tin with paper muffin cases.
Mix flour, baking soda and cinnamon together.
Add egg and yoghurt, mix well.
Add apple and mix to combine.
Divide evenly among 12 paper muffin cases. They should be about 3/4 full.
Bake for approx 20 mins.