Combine all ingredients in a blender. Blend until smooth. (If it isn't as thick as you want it, add a handful of ice cubes and blend again until smooth.)
Pour into a glass, and enjoy!
Notes
*If you don't have a pre-frozen banana, use a regular banana and add a handful of ice. Be aware this will mute the flavor a bit.Recipe variations:
If you’re not into having texture in your smoothies, feel free to leave out the oats, or blend them into a very fine powder before adding the other ingredients.
If you want a sweeter smoothie or a stronger Nutella flavor, use 1/3 cup Nutella instead.
If you don't have Nutella, use a nut butter like peanut butter, and add 1-2 teaspoons of maple syrup for sweetness.