Begin by melting the unsalted butter and creamy peanut butter together. You can do this in a microwave-safe bowl, microwaving in 15-second intervals, stirring in between until you achieve a smooth consistency.
Once the butter and peanut butter are melted and combined, add the powdered sugar and vanilla extract to the bowl. Using a spatula or wooden spoon, mix everything together until it forms a thick and sticky dough.
Gently fold the Rice Krispies cereal into the mixture until well coated.
Using your hands, take small portions of the mixture and roll them into balls—aim for about 1 inch in diameter. Place on a parchment-lined baking sheet and refrigerate for about 30 minutes to set.
While the Rice Krispie balls chill, melt the chocolate chips using the microwave-safe bowl in intervals and stirring until smooth.
Dip each chilled ball into the melted chocolate, ensuring they are fully covered. Use a fork to lift them out, allowing excess chocolate to drip off.
Return the dipped balls to the parchment-lined sheet and let them set at room temperature or in the fridge until the chocolate hardens.
Notes
These treats are perfect for making in advance and can be stored in the freezer for up to three months.