Line cookie sheet with parchment paper.

Mix together peanut butter, butter, and vanilla.

Gradually add the powdered sugar, stirring it into the mixture until it is incorporated.

Roll into 1-inch balls and place on the prepared sheet.

Insert a toothpick into each ball.

Place in freezer until hard (about 30 minutes).

Combine the chocolate chips and shortening.

Melt by microwaving for 1 minute, then stirring and repeating until smooth and melted.

Use the toothpick to dip into the chocolate (leave a small circle uncoated on top of each).

Gently shake off excess and place back on sheet.

Refrigerate several hours until chocolate sets.

Remove toothpicks and smooth over the hole.