In a blender, combine the almond milk, banana, rolled oats, protein powder, cinnamon, maple syrup, vanilla extract, and nutmeg (if using).
Blend on high until smooth and creamy. If you prefer a thicker shake, add ice cubes and blend again until you reach your desired consistency.
Taste the shake and adjust sweetness by adding more maple syrup if needed.
Pour the shake into a glass and sprinkle a pinch of cinnamon on top for garnish.
Serve immediately and enjoy your delicious cinnamon roll protein shake!