Place the oat milk, frozen banana slices, and rolled oats into the canister of a high-speed blender.
Add the almond butter, ground cinnamon, vanilla extract, pitted Medjool date, and sea salt.
Top the mixture with ice cubes to ensure proper emulsification.
Secure the blender lid and initiate processing on the lowest speed setting, quickly increasing to the highest speed.
Blend for 45 to 60 seconds until the mixture is completely smooth and the date is fully incorporated.
Pour into a glass and serve immediately, optionally garnished with a dusting of cinnamon.