Add the ice cream, milk, sugar, vanilla and raw egg, if you are using it, into a blender.
Blend well until all the ingredients are combined; this will take 1 - 2 minutes depending upon the strength of your blender.
Pour into a large glass. Serve immediately.
The raw egg is entirely optional here. If you do decide to include it, be sure to use pasteurized eggs, and respect the best before dates. As well, we would strongly recommend avoiding raw eggs if you are pregnant or immunocompromised.