Beat the confectioners' sugar, peanut butter, melted butter, vanilla and salt with an electric mixer until well combined. Form into 1-inch balls and place on a parchment-lined baking sheet. Freeze until firm, about 20 minutes.
Put the chopped chocolate and shortening in a medium, microwave-safe bowl. Microwave for 2 minutes, stirring every 30 seconds until the mixture is completely melted and smooth.
Stick a toothpick or skewer into the top center of each peanut butter ball. Dip the balls into the melted chocolate, leaving a circle of peanut butter still visible. Allow the excess chocolate to drip off and place on a parchment-lined baking sheet.
Freeze the buckeyes until firm, about 30 minutes. Smooth out the hole left by the toothpick with an offset spatula. Serve at room temperature or well chilled.
Recipe courtesy of Treva Chadwell for Cooking Channel