In a medium bowl, combine the rolled oats, coconut milk, Greek yogurt, shredded coconut, maple syrup, vanilla extract, ground cinnamon, and salt. Stir until well mixed.
If using, gently fold in the sliced bananas.
Divide the mixture evenly into two jars or containers with lids.
Seal the jars and refrigerate overnight (or for at least 4 hours) to allow the oats to soak and soften.
Before serving, give the oats a good stir. Top with fresh whipped cream and additional shredded coconut if desired.
