Line a large baking tray with baking paper or spray with non-stick cooking spray.
Add the yoghurt, and egg to a large mixing bowl and mix well.
Peel and mash up the banana and add to the egg mixture. Mix well.
Add the oats, chocolate chips or dried fruit, ground cinnamon to the bowl and mix.
Cover the bowl with plastic wrap and place in the fridge for around 15 minutes.
Preheat the oven to 180˚C (350˚F).
Using a tablespoon, divide the dough into 12 cookies on the baking tray.
Flatten the top of the cookies with a fork. These cookies will keep their shape while baking.
Bake in preheated oven for around 15 - 20 minutes, until the middle of the cookie is set.
Allow to cool on the baking tray for 10 minutes before transferring to a wire rack.
Store in an airtight container in the fridge for up to 5 days.
Wrap individually, then store in the freezer after cooking for up to two months. Just remember to thaw overnight in the fridge before eating. They can also be reheated in the microwave or in the oven to your desired temperature.
Nutritional information is an estimate and provided as a courtesy. The values may vary according to the ingredients and tools that are used. Please use your preferred nutritional calculator for more detailed information.