Combine powdered sugar, peanut butter and butter in a large bowl. Beat with an electric mixer on medium until smooth. Add cereal and gently stir until thoroughly combined.
In a microwave-safe bowl, melt chocolate on HIGH for 2 minutes; stir. Melt in 30-second increments, stirring after each one, until completely melted.
Roll peanut butter mixture into 1-inch balls. Using a fork or skewer, dip each ball in chocolate until completely covered. Gently shake off excess.
Place peanut butter balls on a cookie sheet covered with wax paper until chocolate is firm. Refrigerate if kitchen is warm. Store in a tightly sealed container at room temperature.
Servings: 100 peanut butter balls