In a microwave-safe bowl, combine the peanut butter, chocolate chips, butter, and salt. Heat the mixture in the microwave in 20-second intervals, stirring after each interval until smooth and fully melted. If desired, stir in the vanilla extract.
Pour the melted peanut butter-chocolate mixture over the cereal. Gently stir to coat each piece evenly, taking care not to crush the cereal.
Divide the coated cereal into 2 batches. For the first batch, use a large resealable plastic bag and layer as follows: 1/2 cup powdered sugar, and half the cereal mixture, followed by another 1/2 cup of powdered sugar. Seal the bag and shake well until the cereal pieces are well-coated with sugar. Remove the contents to a clean bowl. Repeat this process for the second batch of cereal, then combine both sugar-coated batches in the same bowl.
To the bowl of sugar-coated cereal, add the broken pretzels, mini Reese’s cups, and 3/4 cup of the M&M’s or Reese’s Pieces. Gently mix to incorporate. Sprinkle the remaining 1/4 cup of M&M’s or Reese’s Pieces over the top for decoration.
Notes
Note 1: The type of chocolate chips affects the final taste. Milk chocolate chips will make the mixture sweeter and creamier, while semi-sweet chips will provide a richer, more robust chocolate flavor. Use high-quality chocolate chips for the best melting and flavor.Note 2: If you can’t find minis Reese’s, just chop up some regular-sized Reese’s peanut butter cups. If you like Trader Joe’s, try their milk chocolate mini peanut butter cups—they’re my fave!Storage: Serve immediately, or keep leftovers in an airtight container at room temperature. Alternatively, you can freeze it and enjoy straight from the freezer (so good!)