Mix together the powdered sugar, peanut butter, and butter. Add the milk one tablespoon at a time until it becomes a nice workable dough. It will be just like play dough, it will be really easy to work with. Form the dough into egg shapes, and place in the freezer for about an hour.
Place the chocolate chips and shortening in a glass measuring cup. Microwave 1 minute at a time stirring in between until completely melted. (You can also use a double boiler if you prefer, but I am lazy)
Dip each egg in the melted chocolate and place on waxed paper until set. (I use a skewer and then slide the dipped egg of and cover the hole)
Once they are set you can trim any excess chocolate off that may pool at the base with a pairing knife to make them look pretty. You could also decorate them with royal icing and make a really special Easter treat.