Pour the oats into a mixing bowl and add the cinnamon, salt, and vanilla extract; stir together to evenly distribute the spices.
Pour in the milk and maple syrup, then whisk or stir vigorously until the mixture is smooth and the oats are evenly coated.
Transfer the mixture into a jar or airtight container, spreading it out evenly with the back of a spoon or spatula.
Seal the container tightly and place it in the refrigerator overnight, allowing the oats to soak and absorb the flavors.
The next morning, remove the oats from the fridge and give the mixture a gentle stir to loosen it up.
Spoon the creamy oats into bowls and top with your favorite toppings such as nuts, fresh fruit, or a drizzle of honey or caramel for extra flavor and texture.