Combine chilled milk,cocoa powder,vanilla extract,sugar and nutella hazelnut spread in a blender jar and blend it till it is smooth and frothy.Then take a tall glass and 1 tsp hazelnut spread,with the help of a spoon make random swirls inside the wall of the glass.Now pour the shake in it and serve chilled.This is a super easy drink which you can make in no time and almost every kids favorite.You can also garnish with some chocolate chips or flakes.Enjoy !!