Firstly, preheat your oven to 320°F/ 160°c (140°c Fan). Now line two baking trays with parchment paper and place to one side.
Now, using a fork mash the banana in a large mixing bowl until you achieve a smooth and silky consistency. Then you can also incorporate the melted coconut oil and maple syrup.
Now, to a second bowl add all of the dry ingredient (excluding the sultanas) mixing them with a wooden spoon until combined.
Next, begin transferring ½ of the dry mix into the wet mix. Stir this thoroughly to form an even mixture. Then, continue adding in the next ½ of dry mix, making sure all flour and sugar is fully incorporated.
You now can pour in all of the sultanas - again stirring thoroughly to evenly incorporate them through your mixture.
Take a large tbsp of the mixture and shape it into roughly a walnut size ball, placing it onto a baking tray. Continue this until all of your cookie mixture is on both trays.
There is little need to flatten the mixture as they will spread out in the oven, but roughly make the perimeters more circular. They don't need to be perfect, just make sure they will not fall apart or burn.
Place them in an oven for approximately 15 minutes, alternate the baking trays half way through the cooking period (around 7 minutes) so they have received the heat fairly.
Remove from the oven once golden and firm or continue to cook for a few minutes longer if you prefer an even crunchier cookie. Allow these to cool for approximately 10 minutes, before transferring them onto a cooling rack and devouring!!