Add all ingredients to a blender and blend well until smooth. If using a low powered blender, or a small blender like a magic bullet try blending the dry ingredients to a powder first if using either of them, then add the milk, vanilla and banana and blend until smooth before adding the blueberries and blending again until everything is smooth. Otherwise I find the blueberries freeze the milk and make it difficult to blend. If you'd rather use fresh blueberries, use a frozen banana for a creamier milkshake or add a handful of ice just to cool it down. Enjoy!