In a bowl or mason jar, combine the rolled oats, almond milk, and ground cinnamon.
Stir well until all the oats are evenly coated.
Cover and refrigerate for at least 2 hours, preferably overnight.
If you prefer a layered presentation, begin by spooning a few tablespoons of the soaked oats into a serving jar.
Sprinkle in some ground flaxseed or chia seeds, followed by a layer of diced apples.
Add another layer of oats, then raisins or chopped dates.
Continue layering until all ingredients are used.
Finish with chopped walnuts and an extra dusting of cinnamon.
Serve chilled or allow the oats to sit at room temperature for a few minutes before enjoying.