In a wide-mouth glass jar, combine the rolled oats, cocoa powder, chia seeds, and salt.
Stir the dry ingredients together to ensure the cocoa powder is well-incorporated and lump-free.
Pour in the milk, maple syrup, and vanilla extract.
Stir the mixture thoroughly until the liquid is fully integrated and no dry pockets remain.
Fold in the mini chocolate chips.
Secure the lid on the jar and refrigerate for a minimum of 6 hours, or overnight.
Before serving, stir once more and add an additional splash of milk if a thinner texture is preferred.