Add apple, sugar, maple syrup and cinnamon to small saucepan on medium-low heat, stirring until sugar is melted and boiling (about one minute)
Reduce element to low, cover pot for one minute
Take off lid, continue stirring frequently for about ten minutes until caramel is gooey and apples have softened (easy to pierce with a fork, but not as soft as a boiled potato)
Remove from heat
In a container (that will fit about 3 cups), add oats and milk, stir
Add chopped banana and stir in with chia seeds
Add in caramel apples, stir to combine (or leave on top)
Top with chopped walnuts
Leave in fridge overnight