Line a baking sheet with waxed paper or parchment paper and wet aside
In a medium bowl, mix peanut butter, butter, vanilla, and powdered sugar with hands to form a smooth stiff dough. Shape into balls using about 2 tsp of dough for each ball. Place on prepared pan. Insert wooden toothpick into each ball and refrigerate
In a microwave safe bowl or measuring cup, add semi-sweet chocolate chips and shortening. Microwave in 30 second intervals stirring after each interval until melted and smooth
Remove balls from refrigerator. Dip each ball into melted chocolate. Place on prepared baking sheet chocolate side down. Repeat with remaining balls and refrigerate for about 30 minutes or until set. Remove toothpicks and serve