Melt Butter and Add Flavor: In a small saucepan, melt the unsalted butter over medium heat. Once melted, stir in the vanilla extract and turn off the heat.
Add Peanut Butter: Stir in the creamy peanut butter until the mixture is smooth and well blended. If needed, turn the heat back on to medium to help everything combine smoothly.
Combine with Dry Ingredients: In a large mixing bowl, combine the crispy rice cereal and confectioners' sugar. Pour the warm peanut butter mixture over the cereal and sugar. Stir until the mixture is fully blended and the cereal is evenly coated.
Form the Balls: Use a small ice cream scoop or spoon to portion the mixture onto a parchment-lined baking sheet sprayed with nonstick spray. Wet your hands slightly, then roll each portion into a smooth ball.
Chill: Place the baking sheet with the peanut butter balls in the refrigerator for a few hours or overnight to set and harden.
Prepare the Chocolate Coating: In a microwave-safe bowl, combine the semi-sweet chocolate chips and vegetable shortening. Microwave in 15-second intervals, stirring between each, until smooth and fully melted.
Dip and Coat: Dip each chilled peanut butter ball into the melted chocolate, ensuring it is fully coated. Place the chocolate-coated balls back on the lined baking sheet.
Final Chill: Refrigerate the tray for 15 minutes or until the chocolate has set.