Prepare your workspace: Gather all your ingredients and tools. You will need a saucepan, spatula, mixing bowl, and a parchment-lined baking sheet.
Heat the mixture: In a saucepan, combine 1 cup of milk chocolate chips, 1/2 cup of peanut butter (if using), and 1/4 cup of butter. Melt these over low heat, stirring continuously until smooth and fully combined.
Add flavor: Remove the saucepan from heat and stir in 1 teaspoon of vanilla extract, mixing until well combined.
Incorporate the Rice Krispies: Gradually add 3 cups of Rice Krispies cereal to the chocolate mixture, stirring gently but thoroughly until all the cereal is evenly coated with the chocolate mixture.
Form the balls: Allow the mixture to cool slightly so it’s manageable. Once cool enough, use your hands to roll the mixture into bite-sized balls and place them on a parchment-lined baking sheet.
Chill and set: Refrigerate the prepared balls for 20-30 minutes until they firm up and set properly.
Serve and enjoy: After chilling, serve the Chocolate Rice Krispie Balls as a delightful treat! Be sure to store any leftovers in an airtight container to keep them fresh.