Break the oreos biscuits into smaller pieces the best way to do this is to place the oreos in a plastic and seal it after removing the air. Then you can crush the oreos with a rolling pin of a mallet. You can even crush them with your hands; but this is a bit harder then other methods. You only need to break the oreos up into smaller pieces, then blender will to the rest of the work for you.

Place the vanilla ice cream, milk, crushed oreos into a blender. Blend on high setting until the mixture is smooth

Pour into a glass and add a scope of ice cream and serve. Garnish with twixs, diary milk, whole oreo biscuits, you can also top it off with some crushed oreo.