Preheat your oven to 180C and line a 12 hole muffin tin with cases.
To a large bowl add your mashed banana, vegetable oil, plain yoghurt, eggs and vanilla extract. Whisk until combined and then add your granulated sugar and light brown sugar and whisk again until combined.
Add the rest of your dry ingredients - gluten free flour, xanthan gum, salt, baking powder, bicarbonate of soda and cinnamon. Mix well until everything is combined and then fold in your dairy free chocolate chips.
Divide the mixture between the 12 muffin cases and top with the extra dairy free chocolate chunks.
Bake in the oven for around 20-25 minutes (mine took 22 minutes) until golden brown and a skewer comes out clean.