In a large bowl, combine the rolled oats, chia seeds, brown sugar, mashed bananas, cinnamon, salt, vanilla extract, and milk. Stir thoroughly until everything is evenly mixed.
Cover the bowl with a lid or plastic wrap and place it in the refrigerator for at least 4 hours, or overnight.
Stir once more before serving and finish with your favorite toppings.
Notes
Any variety of brown sugar works well here—light, dark, or standard. Dark brown sugar was used when developing this recipe.