Preheat your oven to 180°C / 350°F. Line a couple of big baking sheets with parchment paper.
In the bowl of a food processor, whiz together the maple syrup, coconut oil, and bananas until smooth. Alternately, you can mash the bananas with a fork and then whisk everything together by hand.
In a large bowl, mix the oats, coconut, walnuts, cinnamon, and salt together. Pour the wet mix over top, and give everything a good stir to mix it together.
Spread the granola in even layers on the prepared baking trays.
Pop into the oven and bake for 30 minutes, pulling the trays out to stir the granola every 10 minutes, and rotating the trays in the oven at least once.
Watch the granola carefully towards the end to be sure the edges don't burn. It should be smelling amazing and golden brown.
Remove from the oven and let cool completely on the trays.
Transfer to a clean glass jar, or you can store in the freezer in plastic bags. Enjoy!