Assuming scoops is required, the following result was found.
as much milk as you wish (I use 1 cup); pour into blender, and add the vanilla and peanut butter. Whirl for 1 minute; add 2 scoops ice cream, then whirl 1 minute more. Servings: 1 Source: http://www.recipes-4u.co.uk/drink/Peanut-Butter-Milkshake.html