In your jar or bowl, add the rolled oats, milk, pumpkin puree, and Greek yogurt. Stir everything together until the pumpkin is fully incorporated and there are no dry clumps of oats left sitting at the bottom.
Pour in the maple syrup, vanilla extract, pumpkin pie spice, and a small pinch of salt. Stir again until the mixture looks evenly colored and the spices are no longer sitting on top.
Sprinkle in the chia seeds and dried cranberries, then give the whole jar one more good stir. The chia seeds need to be distributed evenly so they don't clump together into a soggy pocket overnight.
Seal your jar with a lid or cover your bowl tightly, then place it in the fridge for at least 6 to 8 hours. This resting time lets the oats and chia seeds absorb the liquid and soften into a creamy, pudding-like texture.
In the morning, give the oats a quick stir since some separation is completely normal. Add a splash of extra milk if you'd like it looser, then top with your favorite garnishes before digging in.