Whisk almond milk and whey protein until smooth. Add rolled oats, chia seeds, and pumpkin pie spice and mix until combined.
Layer half of the oat mixture into a resealable container or jar, then top with pumpkin puree and maple syrup, then add the remaining oat mixture. Refrigerate overnight.
Serve chilled or microwave for 1 to 1 1/2 minutes before serving.