Sift the powdered sugar into a large bowl, set aside. In the bowl of an electric mixer beat the butter until creamy and smooth. Slowly add the powdered sugar in batches and let incorporate between batches until all the powdered sugar is added.

Add the milk slowly until the mixture is firm and not sticky. Grab a piece and see if you can flatten it with the palm of your hand without it sticking. (If it sticks you need more powdered sugar, if its dry and crumbly add more milk.) You will use almost all or all of the milk.

Divide the 'dough' in two batches. Sift powdered sugar (heavily sift!!) on your work area and on your rolling pin and roll a piece of the dough into a rectangle shape about the size of a piece of paper. Smear peanut butter on the dough using the back of a spoon. You want an even layer, not too thick.

You want to roll the dough 'long ways' as if it was sushi. The first roll may crack at the fold, but its okay keep on rolling. The quicker you can roll the better shaped the candies will look.

Use a knife and cut 1/2 inch thick pieces. Clean your knife between cuts so the candies stay pretty. Repeat process with the other half of dough.