In a medium pot, combine the water and cinnamon sticks. Bring to a boil, then reduce the heat slightly and let it simmer until the water turns a deep brown and fragrant, about 15–20 minutes.
Remove or strain out the cinnamon sticks.
Add the apple slices to the pot and cook on medium heat until the apples soften
Stir in the soaked oats along with the soaking water. Cook for another 5 minutes, stirring occasionally.
Pour in the milk, let it come to a boil and then remove from heat. Let it cool for 15- 20 minutes.
Transfer the mixture to a blender, add maple syrup, and blend until smooth.