Preheat the oven to 200ºC.
Make the cashew milk by placing the cashews in a bowl, add cold water and cover the nuts by a couple of centimetres, soak them overnight.
Drain the cashews and place in a blender with the 450ml water and blend until smooth, check the consistency and if necessary strain the cashew milk through a strainer.
Place the bananas, 2 tbsp coconut oil, brown/muscovado sugar and pinch of salt in a bowl and toss to coat,
spread the bananas on a baking sheet and bake until caramelized for about 15 to 25 minutes and set aside to cool slightly.
Place the sugar and 4 tbsp water into a small saucepan and over medium heat stir until the sugar has dissolved, add the 4 tbsp coconut oil and teaspoon of salt and stir until combined.
Pour the sugar mixture into in a blender, add the coconut cream, 1 cup cashew milk, bananas (and all caramelised bits in the baking sheet), cinnamon and vanilla and blend until smooth.
Cover and refrigerate the ice cream base until chilled for about 3 hours.
Churn in an ice cream maker according to the manufacturer’s instructions, at the end of churning, add toasted walnuts (if used) and churn until incorporated.
Transfer the ice cream to a suitable container and freeze.
Eat within 7 days with some dried banana chips if desired.