Chop chocolate into very small chunks and butter into 2–3 pieces, and put both into a microwave-safe bowl.
Melt chocolate and butter on medium power in the microwave, stirring every 30 seconds, until smooth. (It will take around 2 minutes.)
Add peanut butter and vanilla extract and mix until smooth. Stir in kosher salt.
Pour cereal into a large bowl and add chocolate-peanut butter mixture. Stir gently until all pieces are coated.
Pour confectioners’ sugar into a large zip-top bag along with the cocoa powder.
Add cereal and shake until well coated. You may need to do this in batches.
Spread onto a cookie sheet in a single layer to cool.
When cool, put into a large bowl and gently stir in pretzels and pink and red Valentine’s Day M&Ms.
Notes
Storage Tips: Muddy Buddies keep well in an airtight container at room temperature for about a week. Put in the refrigerator if you want to keep them for 2 weeks.Expert Tips: A 2-gallon ziplock bag is perfect for this recipe. If you don’t have those, I’d recommend tossing the muddy buddies in two batches in a 1-gallon ziplock bag.Work efficiently once the melted chocolate mixture hits the cereal. Stir gently but without delay to prevent the coating from soaking in and softening the cereal.When removing the cereal from the zip-top bag, leave behind any excess powdered sugar at the bottom. This prevents the finished mix from becoming overly sweet or dusty once the pretzels and candies are added.You might want to reserve some M&Ms and pretzels to add more visual appeal when serving. The candies and pretzels will be dusted with the powdered sugar as you stir them in, so adding some fresh ones on top look inviting.