In a blender, combine the rolled oats, banana, Greek yogurt, milk, almond butter, honey or maple syrup, vanilla extract, cinnamon, and a pinch of salt
Blend on high until the mixture is smooth and creamy. If the mixture is too thick, you can add a little more milk to reach your desired consistency
Add the mixed berries to the blender and pulse a few times until they are incorporated into the smoothie, but still slightly chunky for added textur
If desired, add a couple of ice cubes to the blender and blend until they are crushed and the smoothie is chilled
Pour the smoothie into a glass and garnish with additional berries or a sprinkle of oats, if desired