Prepare the ingredients:

Begin by peeling the ripe banana and cutting it into chunks. Measure out the frozen blueberries and the sugar. Frozen fruit is key here as it creates a thicker, colder, and creamier smoothie. If you’re using fresh blueberries, you may want to add a few extra ice cubes.

Blend the smoothie:

In a blender, combine the banana, frozen blueberries, sugar, ice cubes, and buttermilk. Blend on high until smooth and creamy. If the smoothie is too thick, you can add a little more buttermilk or water to reach your desired consistency.

Serve:

Once the smoothie has reached the desired consistency, pour it into a glass and enjoy immediately. You can even garnish it with a few extra fresh blueberries or a small slice of banana on top for a decorative touch.