Line a baking sheet with waxed paper; set aside.
In a medium bowl, mix peanut butter, butter, vanilla, and confectioners sugar with hands to form a smooth stiff dough.
Shape into balls using 2 teaspoons of dough for each ball.
Place on prepared pan, and freeze for 20 minutes.
Melt shortening and chocolate together in a metal bowl over a pan of lightly simmering water. Stir occasionally until smooth, and remove from heat.
Remove balls from freezer. Insert a wooden toothpick into a ball, and dip into melted chocolate. Return to wax paper, chocolate side down, and remove toothpick. Repeat with remaining balls.
Freeze for 30 minutes to set.