Combine the rolled oats, milk, pumpkin puree, cinnamon, nutmeg, cloves, maple syrup, and a pinch of salt in a mixing bowl.
Stir everything together thoroughly until the mixture is uniformly creamy with no dry oats remaining, and the spices are evenly distributed.
Pour the mixture into a jar or airtight container, smoothing the surface with the back of a spoon.
Seal the jar tightly and place it in the refrigerator overnight or for at least 6 hours to allow the oats to soak and absorb the flavors.
Remove the oats from the fridge in the morning and give the jar a gentle stir to incorporate any settled spices or pumpkin swirl.
Serve the pumpkin spice overnight oats topped with your favorite add-ins like nuts, seeds, or dried fruit if desired, and enjoy a cozy, flavorful breakfast.