Start by collecting all the ingredients. Ensure your banana is frozen for that creamy texture.
In your high-speed blender, combine the oats, cinnamon, and salt. Blend for a few seconds until the oats are finely ground.
Add the frozen banana chunks, almond milk, peanut butter, maple syrup, and vanilla extract to the blender.
Blend on high until everything is well combined and smooth, about 30-60 seconds. If you prefer a thicker consistency, add ice and blend again.
Taste your smoothie. If you want it sweeter, add a touch more maple syrup and blend again.
Pour your Oatmeal Smoothie into a glass or mason jar. Top with a sprinkle of cinnamon or sliced bananas if desired. Enjoy immediately!