Line a large baking sheet or tray with waxed paper or parchment paper and set aside.
In a large mixing bowl, beat together the peanut butter, softened butter, vanilla extract, and powdered sugar until smooth and well combined.
Fold in the crushed Rice Krispies cereal until evenly incorporated.
Scoop about 1 tablespoon of the mixture and roll it into bite-sized balls. Place them on the prepared baking sheet.
Refrigerate the peanut butter balls for at least 30 minutes until firm.
In a microwave-safe bowl, combine the chocolate chips and shortening. Microwave in 30-second intervals, stirring after each interval, until the chocolate is smooth and completely melted.
Using a fork or candy dipping tool, dip each chilled peanut butter ball into the melted chocolate, allowing the excess chocolate to drip off. Return the coated balls to the prepared baking sheet.
Refrigerate for 15-30 minutes, or until the chocolate coating is completely set.
Serve immediately or store for later.
Notes
Refrigerate the peanut butter balls in an airtight container for 2-3 weeks.
Freeze in a freezer-safe container for up to 2-3 months. Thaw in the refrigerator before serving.
For easier dipping, keep the peanut butter balls chilled until you're ready to coat them in chocolate.