Preheat the oven to 100°C (fan)/120°C/gas mark ½. Line a baking tray with non-stick greaseproof baking paper.
First mash your two ripe bananas in a bowl until very smooth. Set aside.
Next mix 200g oats, 100g chopped nuts, 1 tsp ground cinnamon and 20g light brown sugar (if using) together in a large bowl.
Add 60ml sunflower oil and 60ml maple syrup to the bananas and stir.
Pour the banana mixture into the oats and stir until thoroughly combined.
Pour onto your prepared baking sheet and spread out with a wooden spoon.
Bake for 60 minutes, stirring every 20 minutes, until turning brown on top.
Allow to cool on the tray and then add 100g raisins and/or 100g dairy free chocolate chips (if using). Store in an airtight container for up to 5 days.