In a blender, combine the almond milk, protein powder, ground cinnamon, maple syrup, vanilla extract, rolled oats, Greek yogurt, and chia seeds.
Blend on high speed until smooth and creamy. If you prefer a thicker shake, add a handful of ice cubes and blend again until desired consistency is reached.
Taste the shake and adjust sweetness by adding more maple syrup if needed.
Pour the shake into a large glass or two smaller glasses.
Optionally, sprinkle a little extra cinnamon on top for garnish before serving.