Combine apples, brown sugar, butter, cinnamon, and nutmeg in a sauce pan and cook on medium low until apples are softened, but not mushy (10 minutes or so) - or desired texture is reached

Set aside

In a medium size bowl, combine oats, milk, and chia seeds

Spoon half of the oat mixture in a layer evenly in the bottom of 4 - 5 Mason jars, then a layer of half the apple mixture, and repeat with another layer of oat mixture and top each with remaining apples

Top with lids and refrigerate overnight