Mash half the banana to a pulpy consistency. Leave the remaining half with the skin intact for later.
Add the mashed banana, rolled oats, chia seeds, milk and cinnamon to a dish. Stir the mixture until well combined.
In a second dish mix together the syrup, peanut butter and a good pinch of salt.
Cover both dishes and place in the fridge overnight or for a minimum of 4 hours.
To serve, spoon out two thirds of the overnight oats into a glass. Add a tablespoon of the salted caramel sauce. If the sauce is too thick simply heat for 20 seconds in the microwave. Layer over the remaining oat mixture and caramel sauce. Thinly slice over the remaining banana.