Peel a large, ripe banana and break into 6 small chunk. Place in a sealed airtight container and freeze for 4-6 hours until hard.
In the jar of a blender, combine frozen banana chunks, milk, yogurt, and vanilla extract. Blend on high for 1 minute or until completely smooth and no banana chunks remain.
Pour into glasses or cups and serve with straws. Recipe can easily be doubled. Enjoy!