Position knife blade in food processor. Add half each of confectioners' sugar,
peanut butter, and butter; top with cover. Process until thoroughly mixed. Shape
into 1-inch balls. Repeat process.
Combine chocolate and shortening in top of a double boiler; bring water to a
boil. Reduce heat to low; simmer until chocolate melts. Dip each ball in chocolate
until partially coated; place on wax paper until chocolate hardens.