In a bowl or jar, mix rolled oats, milk, pumpkin puree, and chia seeds until fully combined and evenly distributed.
Add maple syrup, vanilla extract, pumpkin pie spice, cinnamon, and salt, then stir thoroughly to blend flavors.
Divide the mixture into two sealed containers, leaving space for stirring and toppings later.
Refrigerate overnight for at least 6 hours to allow the oats and chia seeds to absorb liquid and soften.
Stir the oats in the morning and adjust consistency with additional milk if needed.
Add your favorite toppings and serve cold or slightly warmed according to preference.