Put oats, whey, pumpkin, and spice in a jar or small food container.
Add water, and stir.
Cover, and let sit overnight (or at least 4 hours) in the refrigerator.
Stir and enjoy!
Notes
A note about substitutions: You could substitute any kind of protein powder you like (for dairy-free/vegan versions), but you may need more water with other protein powders. Also, if you use quick-cooking steel cut oats, reduce the amount to 3 tablespoons (for this amount of liquid and these macros).